Monthly Archives: December 2021

In This Post we are  providing Chapter-4 MOTION IN A PLANE NCERT MOST IMPORTANT QUESTIONS for Class 11 PHYSICS which will be beneficial for students. These solutions are updated according to 2021-22 syllabus. These MCQS  can be really helpful in the preparation of Board exams and will provide you with a brief knowledge of the chapter.

NCERT MOST IMPORTANT QUESTIONS ON MOTION IN A PLANE

Question 1.
A body is acted upon by the following, velocities:
(i) 7 ms^-1 due to E,
(ii) 10 ms^-1 due S,
(iii) 52–√ ms^-1 due N.E.
Find the magnitude and direction of the resultant velocity.

Answer:
Let OA, OB and OC represent the velocities given in the statement i.e.
OA = 7 ms^-1
OB = 10 ms^-1
and OC = 52–√ ms^-1
To find their resultant velocity, resolve OC into two rectangular components along east and north.

Hence resultant velocity along east = 7 + 5 = 12 ms^-1 and resultant velocity along south = OB – OF = 10 – 5 = 5 ms^-1.

If R be the resultant velocity, then the magnitude of R is obtained by applying the parallelogram law of vector addition as

When OG = 12ms^-1 and OH 5ms^-1.

The direction of R: Let θ be the angle made by R with the east.
∴ in rt. ∠d ΔOGI,

Question 2.
A projectile is fired horizontally with a velocity of 98 ms^-1 from the top of a hill 490 m high. Find:
(i) the velocity with which it strikes the ground.
(ii) the time is taken to reach the ground.
(iii) the distance of the target from the hill.
Answer:

(i) h = 490 m, a = g = 9.8 ms²
U_y = initial velocity along the y-axis at the top of the tower = 0

(ii) Let v be the velocity along the y-axis with which the projectile hits the ground.

If V be the resultant velocity of hitting the ground

Let θ be the angle made by V with the horizontal

(iii) Let x, be the distance of the target from the hill.
∴ x = horizontal distance covered with u in a time t.
ut = 98 × 10 = 980 m.

Question 3.
A boy stands at 78.4 m from a building and throws a ball which just enters a window 39.2 m above the ground. Calculate the velocity of the projection of the ball.

Answer:
Let the boy standing at A throw a ball with initial velocity u.
θ = angle of the projection made with the horizontal.

As the boy is at 78.4 m from the building and the ball just enters above the ground.

Question 4.
Two particles located at a point begin to move with velocities 4 ms^-1 and 1 ms^-1 horizontally in opposite directions. Determine the time when their velocity vectors become perpendicular. Assuming that the motion takes place in a uniform gravitational field of strength g.

Answer:
Let v₁ and v₂ be the velocities of first and 2nd particles respectively after a time t.
∴ v₁ = 4î – gt ĵ
v₂ = – î – gt ĵ
For v₁ and v₂ to be ⊥ to each other, then their dot product must be zero.

Question 5.
A body is projected with a velocity of 40 ms^-1. After two seconds, it crosses a verticle pole of 20.4 m. Find the angle of projection and the horizontal range.

Answer:
Here, u = 40 ms^-1
height of vertical pole, h = 20.4 m
t = 2 seconds

Let us take vertical motion

∴ The horizontal range is given by the relation,

Question 6.
The greatest and the least resultant of two forces acting at a point are 29 N and 5 N respectively. If each force is increased by 3 N, find the resultant of two new forces when acting at a point at an angle of 90° with each other.

Answer:
Let A and B be the two forces.
∴ Greatest Resultant = A + B = 29 N ….(1)
least Resultant = A – B = 5 N ….(2)

Let A and B be the new forces such that
A’ = A + 3 = 17 + 3 = 20N and
B’ = B + 3 = 12 + 3 = 15 N

Here, θ = angle between A’ and B’ = 90°
Let R be the resultant of A’ and B’.
∴ according to parallelogram law of vector addition

The direction of R:
Let β be the angle made by R with A’

Question 7.
An aircraft is trying to fly due north at a speed of 100 ms^-1 but is subjected to a crosswind blowing from west to east at 50 ms^-1. What is the actual velocity of the aircraft relative to the surface of the earth?

Answer:
Let V_a and V_w be the velocities of aircraft and wind respectively.
∴ V_a = 100 ms^-1 along N direction
V_w = 50 ms^-1 along E direction

If V be the resultant velocity of the aircraft, then these may be represented as in the figure given below. So the magnitude of V is given by,


Let ∠AOB = θ be the angle which the resultant makes with the north direction.

Question 8.
Calculate the total linear acceleration of a particle moving in a circle of radius 0.4 m at the instant when its angular velocity is 2 rad s^-1 and angular acceleration is 5 rad s^-2.

Answer:
Since the particle possesses angular acceleration, so its total linear acceleration (a) is the vector sum of the tangential acceleration (a,) and the centripetal acceleration (ac). a₁ and a_c, are at right angles to each other.
a = \sqrt{a_{t}^{2}+a_{c}^{2}} …. (1)

Question 9.
An airplane flies 400 km west from city A to city B then 300 km north-east to city C and finally 100 km north to city D. How far is it from city A to city D? In what direction must the airplane go to return directly to the city A from city D?

Answer:
Given, AB = 400 km
BC = 300 km
CD = 100 km
AD =?

Let N₁, N₂ represent north directions.
∠ABC = 45°
Draw CC’ ⊥ AB, And CB’ ⊥ BN₂
Now in ΔBC’ C

From AAC’D, AD is given by

Question 10.
Which of the following quantities are independent of the choice of the orientation of the coordinates axes:
a + b, 3a_x + 2b_y, [a + b – c], angle between b and c, a?

Answer:
a + b, |a + b – c|, angle between b and c, a are the quantities that are independent of the choice of the orientation of the coordinate axes.

But the value of 3a_x + 2b_y depends on the orientation of the axes.

In This Post we are  providing Chapter-3 MOTION IN A STRAIGHT LINE NCERT MOST IMPORTANT QUESTIONS for Class 11 PHYSICS which will be beneficial for students. These solutions are updated according to 2021-22 syllabus. These MCQS  can be really helpful in the preparation of Board exams and will provide you with a brief knowledge of the chapter.

NCERT MOST IMPORTANT QUESTIONS ON MOTION IN A STRAIGHT LINE

Question 1.
A rocket is fired vertically from the ground. It moves upwards with a constant acceleration of 10 ms^-2 for the 30s after which the fuel is consumed. After what time from the instant of firing, the rocket will attain the maximum height? Take g = 10ms^-2.

Answer:
Here, a = g = 10ms^-2 for t = 30s
∴ u = 0 for first part of the motion
v = velocity attained by the rocket after 30s = ?

∴ using the relation,
v = u + at …(1)
we get v = 0 + 10 × 30
= 300 ms^-1

for second part of motion,
u = v = 300 ms^-1
v₁ = final velocity = 0

Let t1 be the time of journey for this part of the motion,
∴ from equation (1), we get
0 = 300 – 10 × t₁

Let T = total time of flight in which the rocket attains maximum height,
T = t + t₁
= 30 + 30
= 60 second.

Question 18.
On a foggy day, two car drivers spot each other when they are just 80 m apart. They were travelling at 72 km h^-1 and 60 km h^-1 respectively. Both of them simultaneously apply brakes which retard both the cars at 5ms-2. Tell whether they will avert a collision or not?
Answer:
Here, let u, and u2 be the initial velocities of the two cars.

If S1 and S2 be the distances covered by the two cars before coming to rest (i.e. v = 0), then
using the relation,

If S be the total distance covered by two cars before coming to rest, then
S = S₁ + S₂ = 40 + 27.7 = 67.7 m.

Also S₁ = 80 m.
Now clearly the total distance covered by the cars before coming to rest is less than 80 m, so the collision will be averted.

Question 2.
A stone is dropped from a rising balloon at a height of 76 m above the ground and reaches the ground in 6s. What was the velocity of the balloon when the stone was dropped?

Answer:
Let u be the velocity of the balloon in an upward direction at the point
A = initial velocity of stone in an upward direction.

The stone rises to the top, comes to rest and then it starts coming back to the ground to hit B.

Let us take A as origin :
∴ Net vertical distance covered by the stone, y = – 76 m.
a = – g = – 9.8 ms^-2
(Here y and acc. are taken as -ve because they are in a downward direction w.r.t. A)

Question 3.
A car moves at a velocity of 2.24 km h^-1 in the first minute, at 3.60 km h^-1 in the second minute and at 5.18 km h^-1 in the third minute. Calculate the average velocity in these three minutes.

Answer:
Let x₁, x₂ and x₃ be the displacements of car in 1 st, 2nd and 3rd minutes respectively and let v₁, v₂ and v₃ be the velocities of these time intervals,

∴ v₁ = 2.24 kmh^-1, v₂ = 3.60 kmh^-1, v₃ = 5.18 kmh^-1
time intervals = t₁ = t₂ = t₃ = 1 minute = 160 h

If x be the total displacement, then

If v be the average velocity in these 3 minutes, then

Question 4.
A man is walking due East at the rate of 3 km h^-1. Rain appears to fall down vertically at the rate of 3 km h^-1. Find the actual velocity and direction of the rainfall.

Answer:
Let a = angle made by the rainfall with the vertical Velocity of man represented by OA due East = 3 km h^-1
As rain appears to fall vertically downward, so OB = 3 km h^-1 represents the velocity of rain w.r.t. man. The actual velocity of rainfall is represented by OC and is given by

Thus the rain is actually falling at 32–√ km h^-1 at an angle of 45° west of the vertical.

Question 5.
A car starting from rest and moving with uniform acceleration possesses average velocities 5 ms^-1, 10 ms^-1 and 15 ms^-1 in the first, second and third seconds. What is the total r distance covered by the car in these three seconds?

Answer:
Here, let v₁, v₂ and v₃ be the average velocities of 1st, 2nd and 3rd secs, respectively.
∴ v₁ = 5 ms^-1, v₂ = 10 ms^-1, v₃ = 15 ms^-1
t₁ = t₂ = t₃ = 1 s = time intervals

If x₁, x₂ and x₃ be the distances covered in these seconds resp., then

Question 6.
A person is running at a maximum speed of 3 ms-1 along the length of a train to catch hold of the door of a compartment. When he is just 2.5 m from the door, the train steams off with an acceleration of 1 ms^-2. Find how long it takes him to catch the door?
Answer:

Here, let u₁ = 3 m s^-1, be the initial speed of man at point A.
For train x₁ = 2.5 m = distance of the train from man.
u = 0, a = acceleration of train = 1 ms^-2

Let C be their meeting point after a time t.
If BC = x, then usirig the relation,
S = ut + 12 at2, we get

For train, x = 0 + 12 × 1 × t² = 0.5t² … (1)
For man, using the relation,

∴ t = 1, 5 i.e. he will catch the door first after Is and then after 5s.
t = 1s.

Question 7.
The displacement of a body along the x-axis changes according to the relation: x = 20 – 15t + 4t², where x is in metres, t in seconds. Determine its position, velocity and acceleration at t = O.

Answer:
Here, x = 4t² – 1 5t + 20 … (1)
v = dxdt = 4.2t – 15 = 8t – 15 …(2)

Also a = dvdt = 8
At t = 0, the position (x), velocity (y) and acceleration (a) are given by
x = 4.0 – 15 × 0 + 20 = 20 m
v = 8 × 0 – 15 = – 15ms^-1
and a = 8 ms^-2.

Question 25.
A body undergoes a uniformly accelerated motion. Its velocity after 5 seconds is 25 ems and after 8 seconds it is 34 cms’. Calculate the distance covered in the 12th second.
Answer:
Let u and a be the initial speed and acceleration of the body.
Let v₁ and v₂ be its velocities after 5s and 8s respectively

Let S_nth be the distance covered in the 12th second.

Using the relation,

Value-Based Type:

Question 8.
On a two-lane road, there are hoardings hanged on the electric poles “Save Energy”.
If car a is travelling at a speed of 54 km h1 and car ‘B’ moves with 90 km h^-1 from the opposite direction.
Now, answer these questions:
(a) Which values are depicted in the above problem? Write down the four ways by which the energy can be saved.

Answer:
Save energy to save our environment.

The four ways to save energy are as under :

1. By using CFLs, switching off appliances when not in use.
2. Saving water by using it efficiently.
3. Using solar energy.
4. By using public transport.

(b) Write a slogan on “save energy”.
Answer:
Try to switch of the fans and lights when you are not using it. Use limited non renewable sources of energy.

(c) Find the velocity of B with respect to A? Also, find the velocity of the ground with respect to B?
Solution:
V_A = + 54 km h^-1 = 15 ms^-1
V_B = 90 km h^-1 = – 25 ms^-1

(Takingthe velocity of car A positive N v and car B negative)
∴ Relative velocity of B with respect to A
= V_B – V_A = – 25 – 15 = – 40 ms^-1

i.e. the car Boppers to A to move with a speed 40 ms-1 from opposite direction.
Relative velocity of ground w.r.t B = 0 – V_B = 0 – (- 25)
= 25 ms^-1

Question 9.
A candle march was organized by an NGO. The theme of the candle march was “No use of non-biodegradable products”. The organizer made a semicircular track of radius R on which peoples have to run taking a poster in their hands. If Mahesh travelled from A to B in time t with constant speed, then answer the following:

(i) Why should non-biodegradable products not be used? Justify your answer.
Answer:
Biodegradable products are reusable and cause less pollution. So, non-biodegradable products must be avoided.

(ii) Find the
(a) Displacement
Answer:
Displacement = minimum distance between initial and final point = AB = 2 R

(b) Average speed
Answer:

(c) Average velocity
Answer:

(d) Average acceleration
Answer:

Question 10.
In sports day activities of a public school, the lines were drawn with chalk powder. Gagan an athlete runs a distance of 1500 m in the following manner, (i) Starting from rest, he accelerates himself uniformly at 2ms_1, till he covers a distance of 900 m. (ii) He then runs the remaining distance of 600 m at the uniform speed developed.

(i) Which value is depicted in the above problem?
Answer:
Importance of sports activities.

(ii) Do you think that sports activities are important in day-to-day life?

Answer:
Yes, sports activities are very much important in day-to-day life as
(a) It gives break from regular life
(b) It improves physical strength
(c) It relaxes our mind and body
(d) It helps to concentrate on other works
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(iii) Calculate the time taken by the athlete to cover the two parts of the distance covered.
Answer:
Let the athlete run from O to B Here, OB = 1500 m,
OA = 900 m, AB = 600 m

Case II : Taking motion of athelete from A to B u = 60 m/s, S = 600m, a = o (∵ Speed is uniform or constant)
t = t₂ = ?

THINK AS YOU READ:

Q.1 What was Franz expected to be prepared with for school that day?

ANSWER:

Franz was expected to be prepared with participles that day as Mr. Hamel had told the class that he would be taking a test on the topic that day.

Q.2 What did Franz notice that was unusual about the school that day?
ANSWER:
Usually when the school began there would be a lot of commotion. But that day everything was quiet and it appeared to be like a Sunday, but the students were at their places and Mr. Hamel was walking up and down with his terrible iron ruler under his arm.

Q.3 What had been put up on the bulletin-board?

ANSWER:
The bulletin-board notified the general public about an order from Berlin. It stated that only German was to be taught to students in the schools of Alsace and Lorraine.

Q.4 What changes did the order from Berlin cause in school that day?

ANSWER:
The order from Berlin brought all the routine hustle-bustle of the school life to a stand-still. The teacher, M. Hamel, became more sympathetic to his students and taught his lessons with more patience. The students became more attentive in their classes. The villagers, who were sitting at the usually empty back benches and had come to show their respect and gratitude to M. Hamel, regretted not going to school more than they did. The order also brought about a great change in the feelings of the people towards their country and their native language. There was a general sadness about not being able to utilise the opportunities of learning French when it was easily accessible.

Q.5 How did Franz’s feelings about M. Hamel and school change?

ANSWER:
Franz was shocked when M. Hamel told the students about the order from Berlin and that it was their last French lesson. He forgot about his teacher’s ruler and crankiness. He developed a fondness for M. Hamel at the troubling idea of being separated from him forever. He understood the pain and agony his teacher was undergoing. And, he became more sympathetic towards his teacher.
His school too, now, carried a different meaning. His books and lessons seemed old friends whom he couldn’t give up. He realised with pain how much French meant to him and regretted not being attentive in his classes earlier. Suddenly, he felt that the ‘difficult concepts’ had never actually been difficult.

Q.6 The people in this story suddenly realize how precious their language is to them. What shows you this? Why does this happen?

ANSWER:
M. Hamel told the students and villagers that henceforth only German would be taught in the schools of Alsace and Lorraine. Those who called themselves Frenchmen would neither be able to speak nor write it. He praised French as the most beautiful, the clearest and most logical language in the world. He said that for the enslaved people, their language was the key to their prison. Then the people realised how precious their language was to them. This shows people’s love for their own culture, traditions and country. Pride in one’s language reflects pride in motherland.

Q.7 Franz thinks, “Will they make them sing in German, even the pigeons ?” What could this means?

ANSWER:

Alphonse Daudet’s ‘The Last Lesson’ very prominently raises the question of linguistic and cultural hegemony of the colonial and imperial powers and their lust for controlling the world and influencing their cultures and identities. Prussians acquired the districts of Alsace and Lorraine in Franco-Prussian War , but they were not satisfied with mere political domination ,they desired to enforce their own language on the people of the defeated nation. They released the order that from now German would be taught in schools rather than French. Franz wondered whether they would make even pigeons sing in German. It means that they had grown up using French as their language and now snatching away their language from them would be unfair and unkind. The language was as natural to them as cooing is to the pigeon. So, compulsion to speak another language is like dominating the force of nature and enslaving it. As it is next to impossible to alter the way pigeons sing, in the same way it is difficult for people to accept a language which is forcibly imposed on them. Adopting a new language causes pain and discomfort.
OrThis sentence could possibly mean that however hard the authorities try to embed German language in the culture of Alsace and Lorraine, the natural status of French, for them, will remain unchanged. French flows in the air and the entire place is imbued with its effect. Even though they train students in German, the basic mode of communication would remain unchanged like the cooing of the pigeons.

Short Answer Type Question:

Q1. Why do you think was little Franz afraid of being scolded?
ANSWER: Franz was afraid of being scolded that day especially because M. Hamel, the teacher, had said that he would question them on participles. Franz frankly admits that he was totally ignorant about the topic. His exact words are: “I did not know the first word about them.” Secondly, he had started for school very late that morning.

Q2. “It was all much more tempting than the rule for participles.” What did Franz find ‘much more tempting’? How did he finally react?
ANSWER:   Franz found that it was a very warm and bright day. The birds were chirping at the edge of woods. The Prussian soldiers were drilling in the open field at the back of sawmill. He could gladly spend life out of doors. However, he had the strength to resist the temptation. Finally, he hurried off to school.

Q3. “What can be the matter now?” says Franz. Why, do you think, did he make this comment?
ANSWER:   There was a bulletin-board near the town-hall. When Franz passed by it, he noticed a crowd there. He did not stop to look at it. He wondered what could be the matter then. For the last two yeairs they had received all the bad news from the bulletin-board—the lost battle, conscription and the orders of the commanding officer.

Q4. Who was Wachter? What did he ask Franz and why? How did Franz react?
ANSWER:   Wachter was a blacksmith. He was reading the latest bulletin. He asked Franz not to go so fast to his school. He added that the little boy would get to his school in plenty of time. Wachter had read the latest bulletin about teaching of German. Franz thought that the blacksmith was making a fun of him. So, he ran to the school and reached there breathless.

Q5. What was the usual scene when Franz’s school began in the morning?
ANSWER:  Usually, when the school began, there was a great bustle. The noise could be heard out in the school. Students opened and closed their desks. They repeated the lessons together very loudly. They kept their hands over their ears to understand better. The teacher would go on rapping the table with his great iron ruler.

Q6. How had Franz hoped to get to his desk? What had he to do and why?
ANSWER:   Franz had hoped to get to his desk unseen during the commotion. But that day it was very quiet. So, Franz had to open the door and go in before everybody. He blushed as he was late. He was frightened that the teacher might rebuke him, but M. Hamel spoke kindly to him that day.

Q7. What three things in school surprised Franz most that day?
ANSWER:  First, M. Hamel, the teacher had put on his fine Sunday clothes—his beautiful green coat, frilled shirt and the little black silk cap, all embroidered. Second, the whole school seemed quite strange and solemn. Thirdly, the village people were sitting quietly like school children on the back benches that usually remained empty.

Q8. Why had the villagers come to school that day? How did they look?
ANSWER:   The villagers had come there to thank M. Hamel for his forty years of faithful service. They also wanted to show their respect to the country that was theirs no more. They were sorry that they had not gone to school more. They were sitting quietly and looked sad.

Q9. “What a thunderclap these words were to me!” Which were the words that shocked and surprised the narrator?
ANSWER:  M. Hamel, the teacher, told the children in a solemn and gentle tone that it was their last French lesson. Henceforth, only German would be taught in the schools of Alsace and Lorraine. The new master would come the next day. As that was their last French lesson, he wanted them to be very attentive. The teacher’s kind gesture and use of soft words shocked and surprised the narrator.

Q10. How did Franz react to the declaration: ‘This is your last French lesson’?
ANSWER:  The words appeared startling and unexpected like a thunderclap. He now understood why there was a crowd at the bulletin board, why the village people had come to school, why the teacher was dressed in his Sunday best and why there was sadness and silence in the school.

Q11. What tempted Franz to stay away from school? [Delhi 2014]
ANSWER:  Franz was not prepared Tor the test on participles. The Prussian soldiers were drilling in the open field at the back of sawmill. The birds were chirping at the edge of woods. These things tempted him. So he hurried off to school.

Q12. Who did M. Hamel blame for neglect of learning on the part of boys like Franz?
ANSWER:   He thought it typical with the people of Alsace. They would put off learning till tomorrow. Parents are not quite anxious to have their children learn. They put them to work on a farm or at the mills in order to have a little more money. The teacher got his flowers watered or gave them a holiday. He too neglected their lessons.

Q13. What did M. Hamel tell them about French language? What did he ask them to do and why?
ANSWER:  M. Hamel told them that French was the most beautiful language in the world. It was the clearest and the most logical language. He asked them to guard it among them and never _ forget it. He gave a reason also. When a people were enslaved, as long as they held fast to their language, they had the key to their prison.

Q14. Why were the elders of the village sitting in the classroom? [All India 2014]
ANSWER:   M. Hamel was taking the class of last French lesson. That is why elders of the village were sitting in the classroom to attend it. It was done not only to pay respect to M.Hamel but to pay respect to his own language.

Q15. How did Franz and other hoys enjoy their lesson in writing? 
ANSWER:  That day M. Hamel had new copies for them. The words “France, Alsace, France, Alsace” were written on them in a beautiful round hand. The boys set to work quietly. The only sound was the scratching of the pens over the paper. Nobody paid any attention to the beetles who flew in.

Q16. How did M. Hamel feel and behave during the last lesson?
ANSWER:   M. Hamel was solemn and gentle. He sat motionless in his chair during the writing lesson. He gazed at one thing or the other. Perhaps he wanted to fix in his mind how everything looked in that little school room. Surely, it must have broken his heart to leave it all after forty years.

Q17. “He had the courage to hear every lesson to the very last.” What led Franz to make this remark?
ANSWER:   Franz noticed that M. Hamel was feeling sad on having to leave the place sifter 40 years and not being allowed to teach French any longer. Yet, he kept control on his emotions. He performed his duties faithfully. He heard every lesson to the last. The school was dismissed only at mid-day prayer time.

Q18. What happened when the lesson in history was over?
ANSWER:   After the lesson in history was over, the babies chanted their ba, be, bi, bo, bu. Old Hauser, who was sitting at the back of the room, had put on his spectacles. He was holding his primer in both hands. He was spelling the letters with the babies.

Q19. “Ah, how well I remember it, that last lesson!” says the narrator. Which scene does he remember more vividly than the others?
ANSWER:  The narrator remembers the scene of old Hauser spelling the letters from the primer with the babies. He too was crying. His voice trembled with emotion. It was so funny to hear him that all of them wanted to laugh and cry at the same time.

Q20. How did M. Hamel behave as the last lesson came to an end?
ANSWER:   M. Hamel stood up in his chair. He looked very pale and tall. He wanted to say some parting words, but something choked him. Then he wrote “Vive La France!” on the blackboard with a piece of chalk. Then he stopped. He leaned his head against the wall. Without a word, he made a gesture to the students with his hand to permit them to go as the school was over.

Long Answer Type Question:

Q1. Why was Franz scared that day 1 What did he see on his way to school and how did he get to his deski
ANSWER: Franz was not good at learning. He would rather take the day off and waste time in searching birds’ eggs or going sliding on the Saar. Franz was scared that day because M. Hamel had said that he would question them on participles. Franz did not know anything about participles.
He found that the day was warm and bright. The birds were chirping at the edge of the woods. The Prussian soldiers were drilling in the open fields. There was a crowd in front of the bulletin-board near the town-hall.
Franz found the school room unusually quiet. So, he had no option but to open the door and go in before everybody. He blushed and was frightened of the teacher. M. Hamel spoke very kindly to him and asked him to go to his place quickly. Franz jumped over the bench and sat down at his desk.

Q2. What order had been received from Berlin that day? What effect did it have on the life at school?
ANSWER:   An order had been received from Berlin that only German would be taught in the schools of Alsace and Lorraine. This order had far-reaching effects on the life at school. M. Hamel, who had been teaching French at the village school for the last forty years would deliver his last lesson that day.
It was in honour of the last lesson that M. Hamel, the teacher had put on his best clothes. Old men of the village were sitting quietly at the back of the classroom. They were sad as well as sorry for they had not gone to school more. They had come to thank the master for his forty years of faithful service and to show respect for the country that was theirs no more.
The teacher addressed the students in a solemn and gentle tone. He asked them to be attentive and explained everything quite patiently. He appealed to them to preserve French among them. During slavery it would act as key to the prison. He felt so overwhelmed by emotion that he could not bid farewell properly.

Q3. What do you think is the theme of the story ‘The Last Lesson’? What is the reason behind its universal appeal?
ANSWER:  The theme of the story ‘The Last Lesson’ is linguistic chauvinism of the proud conquerors
and the pain that is inflicted on the people of a territory by them by taking away the right to study or speak their own language and thus make them aliens in their own land of birth. The story has a sub-theme also. It highlights the attitudes of the students and teachers to learning and teaching.
Though the story is located in a particular village of Alsace district of France which had passed into Prussian hands, it has a universal appeal. It highlights the efforts of the victors to crush their victims—the vanquished people in all possible manner—materially, spiritually, mentally and emotionally. Taking away mother tongue from the people is the harshest punishment. The proper equation between student and teacher, his focused attention, helpful and encouraging attitude and kind treatment can encourage students to learn better.

Q4. Comment on the appropriateness of the title ‘The Last Lesson’.
ANSWER:  The story has an appropriate and suggestive title. It is the centre of attention throughout and the whole story revolves around it. The beginning of the story serves as preparation for it. The unusual quietness at school, presence of village elders and the teacher in his Sunday best dress—all point out to the unusual and unique occasion—the last lesson in French in a French village school in a district conquered by the Prussians. While delivering the last lesson, the teacher wants to transmit all his knowledge in one go. He explains everything with patience and the students as well as old villagers listen attentively.
For the narrator it is an unforgettable experience. “Ah, how well I remember it, that last lesson,” says he. Old Hauser is crying and his voice trembled with emotion. As the teacher is unable to express His emotions because of choked throat, he ends the lesson by writing Wive La France’ on the blackboard. He makes a gesture with his hand to indicate that the school is dismissed and students can go home.

Q5. What impression do you form ofM. Hamel on the basis of your study of the story ‘The Last Lesson’?
ANSWER:   M. Hamel is an experienced teacher who has been teaching in that village school for forty years. He imparts primary education in all subjects. He is a hard task master and students like Franz, who are not good learners, are in great dread of being scolded by him.
The latest order of the Prussian conquerors upsets him. He has to leave the place for ever and feels heart broken. He feels sad but exercises self-control. He has the courage to hear every lesson to the last.
His performance during the last lesson is exemplary. He is kind even to a late comer like Franz. He uses a solemn and gentle tone while addressing the students. He has a logical mind and can analyse problems and deduce the reasons responsible for it. The problem for Alsace is that he (the district) puts off learning till tomorrow.
He knows the emotional hold of a language over its users. He is a good communicator and explains everything patiently. Partings are painful and being human, M. Hamel too is no exception. He fails to say goodbye as his throat is choked. On the whole, he is a patriotic gentleman.

TEXTBOOK QUESTIONS AND ANSWER:

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Q.1 Differentiate between Balance of Trade and Current Account Balance.
[3 Marks] Or
Distinguish between BOT and Balance on current account.[AI 2008, CBSE 2013, Sample Paper 2013]
ANSWER:

Q.2 Should a current account deficit be a cause for alarm? Explain.[1 Mark]
ANSWER:  No, if deficit in current account is offset by the capital account, otherwise such deficit has to be met by following which is a cause for alarm. 

1. Depleting Foreign Exchange reserves
2. Taking foreign Loans.

Value: Analytic.

Q.3If inflation is higher in country A than in country B, and the exchange rate between the two countries is fixed. What is likely to happen to the trade balance between the two countries?[1 Mark]
ANSWER:  The exports from country B to country A will go up in this situation resulting in improvement or surplus trade balance for B. But due to higher price in country A, its imports will increase for country B and it will lead to deficit in trade balance for country A.

Very Short Answer Type Question:

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Q.1 What does balance of payments account of a country record? [CBSE 2007]

ANSWER:Balance of payments is an accounting statement that provides a systematic record of all the economic transactions between the residents of a country and the rest of the world during a given period of time.

Q.2 What is meant by visible items?
ANSWER:  Visible items include material goods [such as sugar, cloth, machines etc.] which can be seen or touched, counted, measured and weighted and which are duly recorded at the custom barriers.

Q.3 What is the meaning of invisible items?
ANSWER: Invisible items, on the other hand, refer to different kinds of services such as transport, banking, insurance etc.

Q.4 Why are imports entered as negative items in the balance of payments account?
ANSWER:  Imports lead to an outflow of foreign exchange in the country. Thus, they are recorded as negative (debit) items.

Q.5 What is meant by balance of trade? [CBSE 2005, Sample Paper 2010]
ANSWER:  The term “balance of trade” denotes the difference between the exports and imports of goods in a country.

Q.6 Name the items included in balance of trade account. [CBSE 2007]
ANSWER:

1. Exports of visible items (goods);
2. Imports of visible items (goods).

Q.7When will balance of trade show a deficit? [CBSE 2006]
ANSWER:  When imports of visible items are more than exports of visible items.

Q.8 How is a deficit or a surplus on the current account restored?
ANSWER: Deficit on the current account is restored through the surplus on capital account and surplus on the current account is restored through the deficit on capital account.

Short Answer Type Questions :

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Q.1 State four items of current account of BOP account.[CBSE 2004, 08, 08C, 09; AI 05]
Or
Name the broad categories of transactions recorded in the Current account of the balance of payment accounts. [CBSE 2015]
ANSWER: Current account records imports and exports of goods and services and unilateral transfers.
Components of Current Account The main components of Current Account are:

1. Export and Import of Goods (Merchandise Transactions or Visible Trade): A major part of transactions in foreign trade is in the form of export and import of goods (visible items). Payment for import of goods is written on the negative side (debit items) and receipt from exports is shown on the positive side (credit items). Balance of these visible exports and imports is known as balance of trade (or trade balance).
2. Export and Import of Services (Invisible Trade): It includes a large variety of non-factor services (known as invisible items) sold and purchased by the residents of a country, to and from the rest of the world. Payments are either received or made to the other countries for use of these services. Services are generally of three kinds: (a) Shipping,
   (b) Banking, and (c) Insurance. Payments for these services are recorded on the negative side and receipts on the positive side.
3. Unilateral or Unrequisted Transfers to and from abroad (One sided Transactions): Unilateral transfers include gifts, donations, personal remittances and other ‘one-way’ transactions. These refer to those receipts and payments, which take place without any service in return. Receipt of unilateral transfers from rest of the world is shown on the credit side and unilateral transfers to rest of the world on the debit side.
4. Income receipts and payments to and from abroad: It includes investment income in the form of interest, rent and profits.

Q.2What do you mean by capital account and what are its components?
Or
State four items (components) of capital account of BOP account.[CBSE 2004, 11, AI 05]
Or
Name the broad categories of transactions recorded in the Capital account of the balance of payment accounts. [CBSE 2015]
ANSWER:  Capital account is that account which records all such transactions between residents of a country and rest of the world which cause a change in the asset or liability status of the residents of a country or its government.
Components of Capital Account
The main components of capital account are:

1. Loans: Borrowing and lending of funds are divided into two transactions:
   (a) Private Transactions
   • These are transactions that are affecting assets or liabilities by individuals, businesses, etc. and other non-government entities. The bulk of foreign investment is private.
   • For example, all transactions relating to borrowings from abroad by private sector and similarly repayment of loans by foreigners are recorded on the positive (credit) side.
   • All transactions of lending to abroad by private sector and similarly repayment of loans to abroad by private sector is recorded as negative or debit item.
   (b) Official Transactions
   • Transactions affecting assets and liabilities by the government and its agencies.
   • For example, all transactions relating to
   borrowings from abroad by government sector and similarly repayment of loans by foreign government are recorded on the positive (credit) side.
   • All transactions of lending to abroad by government sector and similarly repayment of loans to abroad by government sector is recorded as negative or debit item.
2. Foreign Investment (Investments to and from abroad) It includes:
   (a) Investments by rest of the world in shares of Indian companies, real estate in India, etc. Such investments from abroad are recorded on the positive (credit) side as they bring in foreign exchange.
   (b) Investments by Indian residents in shares of foreign companies, real estate abroad, etc. Such investments to abroad are recorded on the negative (debit) side as they lead to outflow of foreign exchange.
3. Change in Foreign Exchange Reserves
   (a) The foreign exchange reserves are. the financial assets of the government held in central bank. A change in reserves serves as the financing item in India’s BOP.
   (b) So, any withdrawal from the reserves is recorded on the positive (credit) side and any addition to these reserves is recorded on the negative (debit) side.
   (c) It must be noted that ‘change in reserves’ is recorded in the BOP account and not ‘reserves’.

Q.3 Distinguish between current account and capital account of BOP account.[AI 2004, 06 C]
ANSWER:

Q.4 Distinguish between balance of trade and balance of payment. [AI 2004, 06C]
ANSWER:

Q.5 Distinguish between autonomous and accommodating transactions of BOP account. ” [AI 2010; CBSE 10, 13C]
ANSWER:

Q.6 Where is ‘borrowings from abroad’ recorded in the Balance of Payments Accounts? Give reasons. [AT 2015]
ANSWER:

1.  Borrowing from abroad is a part of Capital Account.
2. Borrowing from abroad can be private transactions or official transactions.
3. For example,
   (a) All transactions relating to borrowings from abroad by private sector are recorded on the positive (credit) side as it is inflow of foreign currency.
   (b) Similarly, transactions relating to borrowings from abroad by government sector are recorded on the positive (credit) side as it is inflow of foreign currency.

Q.7 Where will sale of machinery to abroad be recorded in the balance of payment accounts? Give reasons. [CBSE 2015]
ANSWER:

1. Sale of machinery to abroad is a part of Current accounts.
2. Current account records imports and exports of goods and services and unilateral transfers.
3. Sale of machinery to abroad leads to inflow of foreign currency and receipt from exports is shown on the positive side (credit items).

Q.8 What is meant by ‘official reserve transactions’? Discuss their importance in Balance of Payments.[CBSE Sample Paper 2016]
ANSWER:

1. Official reserve transactions are those transactions by a central bank that cause changes in its official reserves.
2. It is sale or purchase of its own currency in the exchange market in exchange for foreign currencies.
3. So, any withdrawal from the reserves is recorded on the positive (Credit) side and any addition to these reserves is recorded on the negative (debit) side.
4. They may be Autonomous and Accommodating Transactions.

In This Post we are  providing Chapter-2 UNITS AND MEASUREMENTS NCERT MOST IMPORTANT QUESTIONS for Class 11 PHYSICS which will be beneficial for students. These solutions are updated according to 2021-22 syllabus. These MCQS  can be really helpful in the preparation of Board exams and will provide you with a brief knowledge of the chapter.

NCERT MOST IMPORTANT QUESTIONS ON UNITS AND MEASUREMENTS

1.E, m, l and G denote energy, mass, angular momentum and gravitational constant respectively. Determine the dimensions of  

Ans:

Thus, it is dimension less.

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2.Two resistances R₁ = 100 and R₂ = 200 are connected in series. Then what is the equivalent resistance?

Ans:

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3.If velocity, time and force were chosen the basic quantities, find the dimensions of mass?  

Ans:

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4.A calorie is a unit of heat or energy and it equals about 4.2 J where . Suppose we employ a system of units in which the unit of mass equals α kg, the unit of length equals  m, the unit of time is y s. Show that a calorie has a magnitude in terms of the new units.

Ans. Given that,

1 calorie = 4.2 (1 kg) 

New unit of mass = α kg

Hence, in terms of the new unit, 1 kg =

In terms of the new unit of length,

And, in terms of the new unit of time,

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5. A SONAR (sound navigation and ranging) uses ultrasonic waves to detect and locate objects under water. In a submarine equipped with a SONAR the time delay between generation of a probe wave and the reception of its echo after reflection from an enemy submarine is found to be 77.0 s. What is the distance of the enemy submarine? (Speed of sound in water = 1450).

Ans. Let the distance between the ship and the enemy submarine be.
Speed of sound in water = 1450 m/s
Time lag between transmission and reception of Sonar waves = 77 s
In this time lag, sound waves travel a distance which is twice the distance between the ship
and the submarine (2S).
Time taken for the sound to reach the submarine
∴ Distance between the ship and the submarine (S) = 1450 × 38.5 = 55825 m = 55.8 km

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6.One mole of an ideal gas at standard temperature and pressure occupies 22.4 L (molar volume). What is the ratio of molar volume to the atomic volume of a mole of hydrogen? (Take the size of hydrogen molecule to be about 1). Why is this ratio so large?

Ans. Radius of hydrogen atom, r = 0.5 = m

Volume of hydrogen atom =

Now, 1 mole of hydrogen contains  hydrogen atoms.

∴ Volume of 1 mole of hydrogen atoms,

Molar volume of 1 mole of hydrogen atoms at STP,

Hence, the molar volume is  times higher than the atomic volume. For this reason, the inter-atomic separation in hydrogen gas is much larger than the size of a hydrogen atom.

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7.The nearest star to our solar system is 4.29 light years away. How much is this distance in terms of parsecs? How much parallax would this star (named Alpha Centauri) show when viewed from two locations of the Earth six months apart in its orbit around the Sun?

Ans. Distance of the star from the solar system = 4.29 ly

1 light year is the distance travelled by light in one year.

1 light year = Speed of light × 1 year

=  m

∴4.29 ly =  m

1 parsec =  m

∴4.29 ly = = 1.32 parsec

Using the relation,

Where,

Diameter of Earth’s orbit, d=

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8.Estimate the average mass density of a sodium atom assuming its size to be about 2.5. (Use the known values of Avogadro’s number and the atomic mass of sodium). Compare it with the density of sodium in its crystalline phase: 970 kg. Are the two densities of the same order of magnitude? If so, why?

Ans.  Diameter of sodium atom = Size of sodium atom = 2.5 

Radius of sodium atom, r =

=  m

Volume of sodium atom, V =

According to the Avogadro hypothesis, one mole of sodium contains  atoms and has a mass of 23 g or  kg.

∴ Mass of one atom =

Density of sodium atom, p =

It is given that the density of sodium in crystalline phase is 970 kg.

Hence, the density of sodium atom and the density of sodium in its crystalline phase are not in the same order. This is because in solid phase, atoms are closely packed. Thus, the inter-atomic separation is very small in the crystalline phase.

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9. It is a well known fact that during a total solar eclipse the disk of the moon almost completely covers the disk of the Sun. From this fact and from the information you can gather from examples 2.3 and 2.4, determine the approximate diameter of the moon.

Ans.

The position of the Sun, Moon, and Earth during a lunar eclipse is shown in the given figure.

Distance of the Moon from the Earth =  m

Distance of the Sun from the Earth = m

Diameter of the Sun =  m

It can be observed that ΔTRS and ΔTPQ are similar. Hence, it can be written as:

Hence, the diameter of the Moon is  m.

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10. Just as precise measurements are necessary in science, it is equally important to be able to make rough estimates of quantities using rudimentary ideas and common observations. Think of ways by which you can estimate the following (where an estimate is difficult to obtain, try to get an upper bound on the quantity):

(a) the total mass of rain-bearing clouds over India during the Monsoon

(b) the mass of an elephant

(c) the wind speed during a storm

(d) the number of strands of hair on your head

(e) the number of air molecules in your classroom.

Ans. (a) During monsoons, a metrologist records about 215 cm of rainfall in India i.e., the height of water column, h = 215 cm = 2.15 m

Area of country, A = 

Hence, volume of rain water, V = A × h =

Density of water, p = 

Hence, mass of rain water = p× V =  kg

Hence, the total mass of rain-bearing clouds over India is approximately  kg.

(b) Consider a ship of known base area floating in the sea. Measure its depth in sea (say).

Volume of water displaced by the ship, 

Now, move an elephant on the ship and measure the depth of the ship () in this case.

Volume of water displaced by the ship with the elephant on board, 

Volume of water displaced by the elephant = 

Density of water = D

Mass of elephant = AD 

(c) Wind speed during a storm can be measured by an anemometer. As wind blows, it rotates. The rotation made by the anemometer in one second gives the value of wind speed.

(d) Area of the head surface carrying hair = A

With the help of a screw gauge, the diameter and hence, the radius of a hair can be determined. Let it be r.

∴Area of one hair = 

Number of strands of hair 

(e) Let the volume of the room be V.

One mole of air at NTP occupies 22.4 l i.e., volume.

Number of molecules in one mole = 

∴Number of molecules in room of volume V

== 

= 

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In This Post we are  providing Chapter-1 PHYSICAL WORLD NCERT MOST IMPORTANT QUESTIONS for Class 11 PHYSICS which will be beneficial for students. These solutions are updated according to 2021-22 syllabus. These MCQS  can be really helpful in the preparation of Board exams and will provide you with a brief knowledge of the chapter.

NCERT MOST IMPORTANT QUESTIONS ON PHYSICAL WORLD

Question 1.
Write the physical principle upon which the working of the gadgets mentioned in the above question is based.

Answer:
These are based on the following physical principles:

1. The boiling point rises with the increase in pressure.
2. Light is produced when the current is passed through a given resistor.
3. Light is emitted when an electric discharge is passed through the gas.
4. A rotating magnetic field is produced on passing current which notates the motor.
5. Due to evaporation of water, cooling in the air which is being forced out by the fan is produced.
6. On absorbing heat from the surroundings, compressed volatile liquid on sudden expansion causes cooling.
7. Current produces a rotating magnetic field that operates the motor.
8. Heat is produced due to the burning of L.P.G.
9. It works on the principle of heating effect of electric current.
10. Torque is produced on the coil due to the electric current passed through it, hence it rotates.
11. Current shows the heating effect when passed through the conductor.
12. It rotates due to the torque produced on the coil on passing an electric current through it.

Question 2.
Name one Scientist each from the following countries who have won Nobel Prize.

(a) Japan
Answer:
H. Yukawa

(b) England
Answer:
Janies Chadwick

(c) India
Answer:
C.V. Raman

(d) The U.S.A.
Answer:
K. Feynman

(e) Germany.
Answer:
Max. Plank.

Question 3.
How Darwin showed that scientific themes are at once simple even though phenomena in nature may be complex.

Answer:
Darwin found a simple basis for the origin of species and descent of man which is “Living things change producing descendants with different characteristics in a process that has been going on for as long as there has been life” by taking a large number of observations on the theory of evolution while onboard ship.

Question 4.
In science sometimes we observed certain phenomena experimentally but are unable to give a logical equation or theory for that sometimes, it also happens that we have a scientific theory supported by’ mathematical formulation yet are unable to test it immediately. Site one such example.

Answer:
Einstein worked to establish a relation between the energy and mass of the body. He was of the view that these are the two sides of the same coin or two facts of the same physical quantity. He succeeded when he gave his mass-energy equation E = mc². But its experimental verification came 40 years later in 1945 when the atomic bomb was exploded over Japan.

Question 5.
Why do we call physics an exact science? What is the aim of science?

Answer:
Physics is called exact science because it is based on the measurement of fundamental quantities.
The main aim of science is to find the truth behind the various processes taking place in the universe.

Question 6.
How science has helped in solving the food problem in several countries?

Answer:
Science has helped in solving food problem in the following ways:
(a) It has given improved and new agricultural implements.
(b) Science has improved the quality of seeds by genetic engineering.
(c) High-yielding hybrid varieties of grains have been developed. Some easily reaping varieties have also been developed and grown.
(d) Use of pesticides and insecticides has saved crops from being destroyed by insects and pests.
(e) Some new types of crops are also developed and are being developed to meet the requirement of society.

Question 7.
What is a scientific temperament and scientific way of doing things?

Answer:
A mindset molded in a particular set of thinking called the scientific way is known as scientific temperament. It is not only based on logic, facts but on reliable observations. The ultimate test of truth in science is experimental verification.

A scientific way of doing things involves the following steps:
(a) Identifying the problem or aim.
(b) Collecting all relevant information or data related to the problem.
(c) Hypothesising or proposing a possible theory.
(d) Taking experimental observation yielding consistent results.
(e) Predicting or making statements.

Question 8.
What is the scope of Physics?

Answer:
The scope of Physics is very wide i.e. the domain of Physics covers a very wide variety of natural phenomena.

For example, the range of distances we study in Physics varies from 10¹⁴ m (size of the nucleus) to 10²⁵ m (size of the universe).

Similarly, the range of masses included in the study of Physics varies from 10^-30 kg (mass of an electron) to 10⁵⁵ kg (mass of the universe). Also, the range of time i.e. time intervals of events we come across in the study of Physics varies from 10²² seconds (time taken by light to cross a nuclear distance) to 10^-8 seconds (lifetime of the sun).

Thus we see that the scope of Physics is really very wide. It includes; optics, electricity waves, and oscillations, heat and thermodynamics, magnetism, atomic and nuclear physics, computers, and electronics.

Question 9.
Physics is an exciting subject! Comment.

Answer:
The study of Physics is exciting in many ways, e g.:

1. Journey to the moon with controls from the grounds.
2. Lasers and their ever-increasing applications.
3. Live transmission of events thousands of kilometers away on the T: V.
4. The speed and memory of the fifth generation of computers.
5. Study of various types of forces in nature.
6. Technological advances in health science.
7. The use of robots is quite exciting.
8. Telephone calls over long distances and so on. Thus, Physics is exciting not only to the scientist but also to a layman, children, women, etc. The musical instruments, toy guns, toy trains, etc. all are constructed using simple principles of physics like collision, potential energy, and vibration, etc. Today the situation is that even our thought process and social values are affected by Physics. Thus, it is quite amazing.

Question 10 .
Write a short note on the origin and development of Physics.

Answer:
Physics as a science took roots from the days of Copernicus, i. e., nearly four centuries ago when it was not well understood and it was considered as a part of philosophy, i.e., knowledge. Later on, with the development of knowledge about nature and its various activities, the knowledge was divided into physical and biological sciences.

Some important developments like Newton’s law of gravitation, ideas about light were developed in the 18th century. The 19th century saw some of the great discoveries in Physics and at the end f the century i.e. 1889, the electromagnetic theory was developed, Fouriuatun of Einstein’s and Plank’s ideas were laid down apart from laying the basis for the industrial revolution. Physics progressed very fast in the first quarter of the 20th century.

Atomic structure, the theory of relativity, quantum theory, nuclear physics, basics of laser theory and most of the other developments took place in this period. Then came transistors, semiconductors, television, radar, and few important discoveries during World War II.

Further development in quantum mechanics, thin-film technology, computers, lasers was developed from 1950 onward. Today we have no theoretical development beyond quantum mechanics. A unified theory is not being tried yet. This is the present status with achievements in applied fields.

TEXTBOOK QUESTIONS AND ANSWER:

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Q.1 How is exchange rate determined under a flexible exchange rate regime? [6 Marks]
Or
How is foreign exchange rate determined? Explain with diagram.
Or [AI 2004; CBSE 06 q How is exchange rate determined in a foreign exchange market? Explain.[AI 2013 (Set 1)]
ANSWER:

1.  Exchange rate in a free exchange market is determined at a point, where demand for foreign exchange is equal to the supply of foreign exchange.
2.  Let us assume that there are two countries – India and U.S.A – and the exchange rate of their currencies i.e., rupee and dollar is to be determined.
   Presently, there is floating or flexible exchange regime in both India and U.S.A. Therefore, the value of currency of each country in terms of the other currency depends upon the demand for and supply of their currencies.
3. In the above diagram, the price on the vertical axis is stated in terms of domestic currency (that is, how many rupees for one US dollar). The horizontal axis measures the quantity demanded or supplied.
4. In the above diagram, the demand curve [D$] is downward sloping. This means that less foreign exchange is demanded as the exchange rate increases. This is due to the fact that the rise in price of foreign exchange increases the rupee cost of foreign goods, which make them more expensive. As a result, imports decline. Thus, the demand for foreign exchange also decreases.
   The supply curve [S$] is upward sloping which means that supply of foreign exchange increases as the exchange rate increases. This makes home country’s goods become cheaper to foreigners since rupee is depreciating in value. The demand for our exports should therefore increase as the exchange rate increases. The increased demand for our exports translates into greater supply of foreign exchange. Thus, the supply of foreign exchange increases as the exchange rate increases.
   
5.  The intersection of the supply and demand curves determine equilibrium exchange rate (OP$) and equilibrium quantity [OQ$] of foreign currency i.e., US [$].

Q.2 Differentiate between devaluation and depreciation. [3 Marks]
ANSWER:

Q.3 Are the concepts of demand for domestic goods and domestic demand for goods the same? [3 Marks]
ANSWER:

1. Demand for domestic goods and domestic demand for goods are two different concepts.
2. Demand for domestic goods is a demand for goods made by both domestic and foreign countries.
3. Domestic demand for goods is a demand for goods by our own country for goods ..which may be produced in foreign countries.

Q.4 Would the central bank need tointervene in a managed floating system? Explain why? [3 Marks]
ANSWER:

1.  In a managed floating system a central bank of a country has freedom to bring change in the exchange rate within certain limits.
2. A country is allowed after information to the IMF to bring a certain limited amount of change in the rate of exchange.
3.  A central bank cannot bring change in its exchange rate by more than 10%. For it, permission of IMF is necessary.

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MORE QUESTIONS SOLVED

Very Short Answer Type Questions :

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Q.1 What is foreign exchange?[CBSE AI 2011, 04]
ANSWER: Foreign exchange refers to all the currencies of the rest of the world other than the domestic currency of the country. For example, in India, US dollar is foreign exchange.

Q.2 What is meant by foreign exchange rate? [CBSE 2004,05,06,09 2011, Sample Paper 2010]
ANSWER:   The rate at which one currency is exchanged for another is called foreign exchange rate.

Q.3 What is meant by foreign exchange market?
ANSWER:  Foreign exchange market is the market where foreign currencies are bought and sold.

Q.4 Define flexible exchange rate system.[CBSE 2008]
ANSWER:   Flexible exchange rate system refers to a system in which the exchange rate of different currencies is determined by the forces of demand and supply in foreign exchange market.

Q.5The price of 1 US Dollar has fallen from Rs. 50 to Rs. 48. Has the Indian currency appreciated or depreciated?[CBSE Sample Paper 2010]
ANSWER:  Indian currency has appreciated.

Short Answer Type Questions :

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Q.1 State four sources of demand of foreign exchange.[CBSE 2004, 05, 05C, 07; A 05, 10] Or
Give three reasons why people desire to have foreign exchange.
Or [CBSE 2005]
What are the sources of demand for foreign exchange?
ANSWER:   The demand (or outflow) of foreign exchange comes from the people who need it to make payments in foreign currencies. It is demanded by the domestic residents for the following reasons:

1. Imports of Goods and Services:When India import goods and services, foreign exchange is demanded to make the payment for imports of goods and services.
2. Tourism: Foreign exchange is demanded to meet expenditure incurred in foreign tours.
3. Unilateral Transfers sent abroad: Foreign exchange is required for making unilateral transfers like sending gifts to other countries.
4. Purchase of assets in foreign countries: It is demanded to make payment for purchase of assets, like land, shares, bonds, etc. in foreign countries.

Q.2 What are the functions of a foreign exchange market?
ANSWER:

1. Transfer Function: Transfer function refers to transferring of purchasing power among countries.
2. Credit Function: It implies provision of credit in terms of foreign exchange for the export and import of goods and services across different countries of the world.
3. Hedging Function: Hedging function pertains to protecting against foreign exchange risks. Where Hedging is an activity which is designed to minimize the risk of loss.

Q.3 Why does demand for foreign exchange rise when its price falls?
Or [AI 2006, 08, 10] What are the reasons for ‘Rise in Demand’ for Foreign Currency?
ANSWER: The demand for foreign currency rises in the following situations:

1. When price of a foreign currency falls, imports from that, foreign, country become cheaper. So, imports increase and hence, the demand for foreign currency rises.
   For example, if price of 1 US dollar falls from Rs 60 to T 55, then imports from The USA will increase as American goods will become relatively cheaper. It will raise the demand for US dollar.
2. When a foreign currency becomes cheaper in terms of the domestic currency, it promotes tourism to that country. As a result, demand for foreign currency rises.
3. When price of a foreign currency falls, its demand rises as more people want to make gains from speculative activities.

Q.4 When price of a foreign currency rises, its demand falls’. Explain why?
Or [CBSE 2011]
Explain relation between foreign exchange rate and demand for it.
Or [CBSE 2004q Why demand curve of foreign exchange is downward sloping?

ANSWER:

1. Demand curve of foreign exchange slopes downwards due to inverse relationship between demand for foreign exchange and foreign exchange rate.
2. In figure, demand for foreign exchange (US dollar) and rate of foreign exchange are shown on the horizontal axis and vertical axis respectively.
3. The demand curve [US$] is downward sloping. It means that less foreign exchange is demanded as the exchange rate increases.
4. This is due to the fact that rise in the price of foreign exchange increases the rupee cost of foreign goods, which make them more expensive. As a result, imports decline. Thus, the demand for foreign exchange also decreases.

Q.5 State four sources of supply of foreign exchange.[CBSE 2004, 05, 05C, 07, 10; AI 05] Or
What are the sources for supply of foreign exchange?
ANSWER:  The supply (inflow) of foreign exchange comes from the people who receive it due to the following reasons.

1.  Exports of goods and services:Supply of foreign exchange comes through exports of goods and services.
2. Foreign investment: The amount, which foreigners invest in their home country, increases the supply of foreign exchange.
3. Remittances (unilateral transfers) from abroad: Supply of foreign exchange increases in the form of gifts and other remittances from abroad.
4. Speculation: Supply of foreign exchange comes from those who want to speculate on the value of foreign exchange.

Q.6 What are the reasons of ‘rise in supply’ of foreign currency?
Or
Why does a rise in foreign exchange rate cause a rise in foreign exchange supply? [CBSE 2006, 08]
Or
When exchange rate of a foreign currency rises, its supply also rises. How? Explain. [CBSE 2008]
ANSWER:   The supply of foreign currency rises in the following situations:

1. When price of a foreign currency rises, domestic goods become relatively cheaper. It induces the foreign country to increase their imports from the domestic country. As a result, supply of foreign currency rises. For example, if price of 1 US dollar rises from Rs 60 to Rs 65, then exports to USA will increase as Indian goods will become relatively cheaper. It will raise the supply of US dollars.
2. When price of a foreign currency rises,foreign direct investment (FDI) from rest of the world increases, which will increase the supply for foreign exchange.
3. When price of a foreign currency rises, also supply of foreign currency rises as people want to make gains from speculative activities.

Q.7 Why supply curve of foreign exchange is upward sloping?

ANSWER:

1. Supply curve of foreign exchange slopes upwards due to positive relationship between supply for foreign exchange and foreign exchange rate, which means that supply of foreign exchange increases as the exchange rate increases.
2.  This makes home country’s goods become cheaper to foreigners since rupee is depreciating in value. The demand for our exports should therefore increase as the exchange rate increases.
3. The increased demand for our exports will translate into greater supply of foreign exchange. Thus, the supply of foreign exchange increases as the exchange rate increases.

Q.8 Explain the effect of depreciation of domestic currency on exports.
[A7 2013 (Set I), Sample Paper 2013]
ANSWER:  Depreciation of domestic currency means a fall in the price of domestic currency (say, rupee) in terms of a foreign currency (say, $). It means, with the same amount of dollars, more goods can be purchased from India, i.e., exports to USA will increase as they will become relatively cheaper.

Q.9 Explain the effect of appreciation of domestic currency on imports.
[CBSE 2013 (Set I), Sample Paper 2013)]
ANSWER: Appreciation of domestic currency means a rise in the price of domestic currency (say, rupee) in terms of a foreign currency (say, $). Now, one rupee can be exchanged for more $, i.e., with the same amount of money, more goods can be purchased from the USA. It leads to increase in imports from the USA as American goods will become relatively cheaper.

Q.10 What are the merits of fixed exchange rate system? [CBSE 2009]
ANSWER:

1. Stability: It ensures stability, in the international money market/ exchange market. Day to day fluctuations are avoided. It helps formulation of long term economic policies, particularly relating to exports and imports.
2.  Encourages international trade: Fixed exchange rate system implies low risk and low uncertainty of future payments. It encourages international trade.
3. Co-ordination of macro policies:Fixed exchange rate helps co¬ordination of macro policies across different countries of the world. Long term economic policies can be drawn in the area of international trade and bilateral trade agreements.

Q.11What are merits of flexible exchange rate system? [CBSE, AI 2009]
ANSWER:

1. No need for international reserves: Flexible exchange rate system is not to be supported with international reserves.
2. International capital movements: Flexible exchange rate system enhances movement of capital across different countries of the world. This is due to the fact that member countries are no longer required to keep huge international reserves.
3. Venture capital: Flexible exchange rate promotes venture capital in foreign exchange market. Trading in international currencies itself becomes an important economic activity.

Q.12 Differentiate between fixed exchange rate and flexible exchange rate? [AI 2015]
ANSWER:

Q.13 Explain the meaning of Managed Floating Exchange Rate? [AI 2015]
ANSWER:

1. Managed floating exchange rate is a mixture of a flexible exchange rate (the float part) and a fixed exchange rate (the Managed part).
2. In other words, it refers to a system in which foreign exchange is determined by free market forces (demand and supply forces), which can be influenced by the invention of the central bank in foreign exchange market.
3. Under this system, also called Dirty floating, central banks intervene to buy or sell foreign currencies in an attempt to stabilise exchange rate movements in case of extreme appreciation or depreciation.

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Textbook Question And Answer:

Q.1Explain why public goods must be provided by the government? [3-4 Marks]
ANSWER:

1. Public goods are those goods and services for which consumption by some individuals does not reduce the amount available to others.
2. For example parks,roads,water,bridges,national defense etc..
3. these goods are non-rival and non-excludable ones.
4. people receives benefits from public goods but do not pay for them.Such a goods can only prepared by government.

Q.2 Distinguish between revenvu expenditure and capital expenditure .
State the basis of classifying government expenditure into revenue and capital expenditure. Give an example of each.
ANSWER:

Q.3 The fiscal deficit gives the borrowing requirement of the government Elucidate. [3-4 Marks]
ANSWER:

1. Fiscal deficit is defined as excess of total expenditure over total receipts (revenue and capital receipts) excluding borrowing. In the form of an equation:
   Fiscal Deficit = Total Budget Expenditure – Total Budget Receipts (Net of borrowing)
   = Total Expenditure (Revenue
   Expenditure + Capital Expenditure) – Revenue Receipts (Tax Revenue + Non-Tax Revenue) – Non-Debt Capital Receipts (Recovery of Loans + Dis-investment Proceeds)
   = Revenue Deficit + Capital Deficit (excluding Borrowing)- Borrowing
   = Net borrowing at home + Borrowing from RBI + Borrowing from abroad
2. Fiscal deficit shows total borrowing requirements of the government from all sources.
3. As the government borrowing increases, its liability in future to repay loan with interest also increases leading to a higher revenue deficit. Therefore, fiscal deficit should be as low as possible.

Q.4 Give the relationship between revenue deficit and fiscal deficit. [3-4 Marks]
ANSWER:

1. Fiscal deficit is always a wider concept than revenue deficit.
2.  Revenue deficit is defined as the excess of government’s revenue expenditure over revenue receipts. In terms of formula:
   Revenue Deficit = Revenue Expenditures (RE) – Revenue Receipts (RR)
3.  In short, there will be revenue deficit in a government budget when revenue expenditure exceeds revenue receipts.
4. Fiscal deficit is defined as the excess for all expenditure over total receipts net of borrowings.
5. Initially, Fiscal deficit does not take into account all types of receipts. It does not take into account borrowings. But finally they have to depend on borrowing to met fiscal deficit.
   Fiscal Deficit = Revenue Deficit + Capital Deficit (Excluding Borrowing)- Borrowing
   = Net borrowing at home + Borrowing from RBI + Borrowing from abroad

Q.5 Does public (government) debt impose a burden? Explain. [3-4 Marks]
ANSWER:   Public debt is not always a blessing. Excessive use of it creates a lot of crisis in an economy; such as,

1. Hampers Economic Development of a Country: Loans are easily borrowed but it is very difficult to repay them.Generally, government imposes more taxes. It brings instability and is an obstacle in the economic development of a country.
2. Poses Threat to Political Freedom: Foreign loans and assistance lead to deep conflict among countries. The friction among countries challenges the political freedom.
3. Proves a Burden on Common Man: Loans taken for unproductive purposes, like war and armaments, are a burden on common man in the form of higher taxes.
4. Leads to Extravagant Spending: Public debt leads to unplanned spending. This provides incentive to the government to implement the schemes that require excessive expenditure.
5. Results in Drain of National Wealth: Repayment of foreign loans results in drain of wealth out of the country.

Q.6 Are fiscal deficits necessarily inflationary? [3-4 Marks]
Or
“Governments across nations are too much worried about the term fiscal deficit”. Do you think that fiscal deficit is necessarily inflationary in nature? Support your answer with valid reasons.
ANSWER:

1. Fiscal deficits are not necessarily inflationary.
2. As we know fiscal deficit shows borrowing requirement of the government.
3. If we borrow when there is a situation of underemployment in an economy i.e., in a situation of deficient demand, then it is not inflationary because in a situation of deficient demand output is held back because of lack of demand.
4. A high fiscal deficit (borrowing) is accompanied by higher demand and greater output which is not inflationary.
5. On the other hand, if we borrow at the full employment level, then it is inflationary in nature.
6. A high fiscal deficit (borrowing) is accompanied by higher prices because aggregate demand is greater than aggregate supply at the full employment level which is always inflationary.

Q.7 Discuss the issue of deficit reduction.[3-4 Marks]
ANSWER: The deficit in a government budget can be reduced by the following steps:

1. Taxes should be increased. Government can make a plan for rising direct taxes to increase its receipts can also be raised by increasing rates of taxes or by imposing new taxes.
2. Reduction in Government Expenditures: It can be done through making government activities more efficient through better planning of programmes and better administration.
3.  The government can raise Receipts through the sale of shares in PSUs (Public Sector Undertaking).
4. Changing the scope and role of government by withdrawing from same areas where it operated before.

Very Short Answer Type Questions :

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Q.1 Define government budget.
  ANSWER:  A government budget is an annual financial statement showing itemwise estimates of expected revenue and anticipated expenditure during a fiscal year.

Q.2 State any one obj ective of a government budget.
ANSWER:  Activities to secure a reallocation of resources

Q.3 Define a tax.
ANSWER:  A tax is a legally compulsory payment imposed by the government on income and profit of persons and companies without reference to any benefit. Tax is of two types: Direct tax and Indirect tax.

Q.4 Why is service tax an indirect tax?
ANSWER: Its impact and incidence lie on different persons.

Q.5 State any two sources of non-tax revenue receipts.
ANSWER:

1. Commercial revenue (profit and interest)
2. Administrative revenueffees, fines and penalties, escheats etc)

Q.6 Is borrowing by the government a revenue receipt?
ANSWER:  No, it is not so because it creates a liability (for the government) of repayment.

Q.7 Why is tax not a capital receipt?
ANSWER:  Tax is not a capital receipt because it leads neither to creation of liability nor to reduction in assets.

Q.8 Why is interest termed as a revenue receipt?
ANSWER:  Interest is a revenue receipt because it creates neither any liability nor causes a reduction in the assets of the government.

Q.9 Why are borrowings a capital receipt?
ANSWER:  They create a liability (in terms of repayment).

Q.10 Why are subsidies treated as revenue expenditure?
ANSWER: Subsidies are treated as revenue expenditure because they create neither any asset nor cause a reduction in any liability of the government.

Q.11 Why is repayment of loan a capital expenditure?
ANSWER: It reduces the liabilities of the government.

Q.12 Why is recovery of loans treated as a capital receipt?[CBSE All India 2005]
ANSWER: Recovery of loans is treated as a capital receipt because it reduces assets of the government.

Q.13 Why are receipts from taxes categorised as revenue receipts?
ANSWER: Receipts from taxes are categorised as revenue receipts because they create neither any liability nor cause a reduction in the assets of the government.

Q.14 What is meant by revenue deficit?
ANSWER: Revenue deficit refers to the excess of revenue expenditure of the government over its revenue receipts. Revenue Deficit = Revenue Expenditure- Revenue Receipts

Q.15 If the revenue receipts are Rs. 1,000 crore and revenue expenditure is Rs. 1,200 crore, how much will be the revenue deficit?
ANSWER:  Revenue Deficit = Revenue Expenditure – Revenue Receipts = 1,200 – 1,000 = Rs. 200 crore.

Q.16Define fiscal deficit.
ANSWER:  Fiscal deficit is defined as excess of total expenditure over total receipts (revenue and capital receipts) excluding borrowing.

Q.17 What is the meaning of primary deficit?
ANSWER:  Primary deficit refers to the difference between fiscal deficit of the current year and interest payments on the previous borrowings.

Q.18 How is primary deficit calculated?
ANSWER: Primary Deficit = Fiscal Deficit – Interest Payments

Q.19 What does zero primary deficit mean?
ANSWER:  If primary deficit is zero, fiscal deficit= interest payments. It means the government has to borrow only for its interest commitments on earlier loans.

Short Answer Type Questions : 

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Q.1 Explain objective of stability of prices of government budget. [CBSE, (F) 2010] Or
Explain the ‘economic stability’ objective of a government budget. [CBSE, AI2011] Or
Explain stabilising activities function of budget.
ANSWER:

1. Free play of market forces (or the forces of supply and demand) are bound to generate trade cycles, also called business cycles.
2. These refer to the phases of recession, depression, recovery and boom in the economy.
3. The government of a country is always committed to save the economy from business cycles. Budget is used as an important policy instrument to combat(solve) the situations of deflation and inflation.
4.  By doing it the government tries to achieve the state of economic stability.
5. Economic stability leads to more investment and increases the rate of growth and development.

Q.2 Name two sources each of non-tax revenue receipts. [CBSE 2004]
ANSWER:  Non-tax revenue refers to government revenue from all sources other than taxes called non-tax revenue. These are incomes, which the government gets by way of sale of goods and services rendered by different government departments. Its two sources are:

1. Commercial Revenue (Profit and interest): It is the revenue received by the government by selling the goods and services produced by the government agencies. For example, profit of public sector undertakings like Railways, BHEL, LIC etc. Government gives loan to State Government, union territories, private enterprises and to general public and earns interest receipts from these loans. It also includes interest and dividends on investments made by the government.
2. Administrative Revenue: The revenue that arises on account of the administrative function of the government. This includes:
   (i) Fee: Fee refers to a payment made to the government for the services that it renders to the citizens. Such services are generally in public interest and fees are paid by those, who receive such services. For example, passport fees, court fees, school fees in government schools,
   (ii) License Fee: License fee is a payment to grant a permission by a government authority. For example, registration fee for an automobile.

Q.3 Distinguish between: Revenue receipts and capital receipts. [CBSE 2005, 10]
Or
Distinguish between ‘revenue receipt’ and ‘capital receipt’ and give two examples of each. [CBSE 2007]
ANSWER:

Q.4 Distinguish between Direct tax and indirect tax.
ANSWER:

Q.5 Differentiate between Revenue Budget and Capital Budget.
ANSWER:

Q.6 Differentiate between Developmental and Non-Developmental Expenditure.
ANSWER:

Q.7 What are the implications of a large revenue deficit? Give two measures to reduce this deficit. [CBSE Sample Paper 2010]
ANSWER:

1. Revenue deficit indicates dis¬savings on government account because the government has to make up uncovered gap.
2. Revenue deficit implies that the government has to cover’this uncovered gap by drawing upon capital receipts either through borrowing or through sale of its assets.
3. Since government is using capital receipts to meet generally consumption expenditure of the government which leads to an inflationary situation in the economy.

Two measures to reduced revenue deficit are :

1. Government should reduce its unproductive or unnecessary expenditure.
2. Government should increase its receipts from various sources of tax and non-tax revenue.

Q.8 What are implications of fiscal deficit? [A/2005; CBSE 06C, 07]
ANSWER:

1. Causes Inflation: An important component of government borrowing includes borrowing from the Reserve Bank of India. This invariably implies deficit financing or meeting deficit requirements of the government by way of printing more notes. This is a dangerous practice, though very convenient for the government. It increases circulation of money and causes inflation.
2. Increase in Foreign Dependence:Government also borrows from rest of the world. It increases our dependence on other countries. Foreign borrowing is often associated with economic and political interference by the lender countries. It increases our economic slavery.
3. Financial Burden for Future Generation: Borrowing implies accumulation of financial burdens for the future generations. It is for future generations to repay loans as well as the mounting interest thereon.
4. Deficits Multiply Borrowings:Payments of interest increases revenue expenditure of the government, causing an increase in its revenue deficit. Thus, a vicious circle set wherein deficits multiply borrowings.

Long Answer Type Question:

Q.1 Explain the role the government can play through the budget in influencing allocation of resources. [CBSE 2015] OR .
Explain the ‘allocation of resources’ objective of government budget.[CBSE 2011] OR
Explain the allocation function of agovernment budget. [CBSE AI2010]OR
Explain how government can influence allocation of resources through government budget.
ANSWER:

1. Private enterprises always desire to allocate resources to those areas of production where profits are high.
2. However, it is possible that such areas of production (like production of alcohol) may not promote social welfare.
3. Through its budgetary policy the government of a country directs ‘ the allocation of resources in a manner such that there is a balance between the goals of profit maximisation and social welfare.
4. Production of goods which are injurious to health (like cigarettes and whisky) is discouraged through heavy taxation.
5. On the other hand, production of “socially useful goods” (like electricity, ‘Khadij is encouraged through subsidies.
6.  So, finally government has to reallocate resources in accordance to social and economic considerations in case the free market fails to do or does so inefficiently.

Q.2 Explain how the government can use the budgetary policy in reducing inequalities of incomes. [AI 2015] OR
How can a government budget help in reducing inequalities of income? Explain. [CBSE 2009]OR
How can a government budget be helpful in altering distribution of income in an economy? Explain.[CBSE 2010] OR
Explain ‘redistribution of income’ objective of government budget. [CBSE2011, A/2011] OR
Reduction in income inequalities raises welfare of the people. How can government help, through government budget, in this regard? Explain? [A/2013, C (Set /)]
ANSWER:

1. Budget of a government shows its comprehensive exercise on the taxation and subsidies.
2.  A government uses fiscal instruments of taxation and subsidies with a view of improving the distribution of income and wealth in the economy.
3.  A government reduces the inequality in the distribution of income and wealth by imposing taxes on the rich and giving subsidies to the poor, or spending more on welfare of the poor.
4.  It will reduce income of the rich and raises the living standard of the poor, thus, leads to equitable distribution of income.
5. Expenditure on special anti poverty and employment schemes will be increased to bring more people above poverty line.
6. Public distribution system should be inferred so that only the poor could get foodgrains and other essential items at subsidised prices.
7. Equitable distribution of income and wealth is a sign of social justice which is as the principal objective of any welfare state in India.

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Very Short Answer Type Questions :

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Q.1. What is meant by excess demand in macroeconomics?
ANSWER: When in an economy aggregate demand exceeds “aggregate supply at full employment level”, the demand is said to be an excess demand.

Q.2 Define inflationary gap.

ANSWER:  When in an economy aggregate demand exceeds “aggregate supply at full employment level”, the demand is said to be an excess demand and the gap is called inflationary gap.

Q.3 Give the meaning of deficient demand.

ANSWER:   When in an economy aggregate demand falls short of aggregate supply at full employment level, the demand is said to be as deficient demand.

Q.4 Define deflationary gap. [CBSE 2008]
OR
Give the meaning of deflationary gap. [CBSE 2010]

ANSWER:  ” When in an economy aggregate demand falls short of aggregate supply at full employment level, the demand is said to be deficient demand and the gap is called deflationary gap.

Q.5 State two measures by which a central bank can attempt to reduce the inflationary gap.
ANSWER: 

1.  Increase in cash reserve ratio.
2.  Increase in marginal requirement.

Q.6. What is the impact of increase in margin requirements?
ANSWER:   Increase in margin requirements discourages borrowings and decreases the aggregate demand.

Q.7 Give the meaning of full employment.[CBSE 2008]
ANSWER:   Full employment equilibrium refers to the situation where aggregate demand = aggregate supply and all those who are able to work and willing to work (at the existing wage rate) are getting work.

Q.8 Give the meaning of involuntary unemployment.[CBSE 2008, 09, Sample Paper 2010]
ANSWER:   Involuntary unemployment refers to a situation in which all able and willing persons to work at existing wage-rate do not find work. They are rendered unemployed against their wish. Hence, it is termed as involuntary unemployment.

Q.9 Is it necessary that equality between AD and AS is established at the full employment level?
ANSWER:   No, it is not necessary that full employment occurs when AD = AS. Equilibrium can be achieved at full employment level, under employment level or at over full employment level.

Q.10 What is meant by full employment equilibrium?
ANSWER:  Full employment equilibrium refers to a situation when equilibrium is attained i.e., aggregate demand is equal to aggregate supply at full employment level.

Q.11 What is underemployment equilibrium?[CBSE 2008]
ANSWER:  Underemployment equilibrium refers to a situation when equilibrium is attained i.e., aggregate demand is equal to aggregate supply below full employment level or when resources are not fully employed.

Q.12 What is the meaning of over full employment equilibrium?
ANSWER:   Over full employment level refers to a situation when equilibrium is attained, i.e., aggregate demand is equal to aggregate supply beyond the full employment level.

Short Answer Type Question:

Q.1 What are the reasons or causes for excess demand?
ANSWER: The main reasons for excess demand are apparently the increase in the following components of aggregate demand:

1. Increase in household consumption demand due to rise in propensity to consume.
2. Increase in private investment demand because of rise in credit facilities.
3. Increase in public (government) expenditure.
4. Increase in export demand.
5.  Increase in money supply or increase in disposable income.

Q.2 What are impacts or effects of excess demand on price, output, employment?
ANSWER: 

1. Effect on General Price Level: Excess demand gives a rise to general price level because it arises when aggregate demand is more than aggregate supply at a full employment level. There is inflation in economy showing inflationary gap.
2. Effect on Output: Excess demand has no effect on the level of output. Economy is at full employment level and there is no idle capacity in the economy. Hence output can’t increase.
3.  Effect on Employment: There will be no change in the level of employment also. The economy is already operating at full employment equilibrium, and hence there is no unemployment.

Q.3 What are the reasons or causes for deficient demand?
ANSWER:  The main reasons for deficient demand are apparently the decrease in four components of aggregate demand:

1. Decrease in household consumption demand due to fall in propensity to consume.
2. Decrease in private investment demand because of fall in credit facilities.
3. Decrease in public (government) expenditure.
4. Decrease in export demand.
5. Decrease in money supply or decrease in disposable income.

Q.4 What are the impacts or effects of deficient demand on price (output) employment?
ANSWER: 

1. Effect on General Price Level:Deficient demand causes the general price level to fall because it arises when aggregate demand is less than aggregate supply at full employment level. There is deflation in an economy showing deflationary gap.
2. Effect on Employment: Due to deficient demand, investment level is reduced, which causes involuntary unemployment in the economy due to fall in the planned output.
3. Effect on Output: Low level of investment and employment implies low level of output.

Q.5 Explain the role of Government expenditure and Open Market Operation in reducing AD/excess demand. [CBSE 2004C, 06, CBSE 2011; A 11]
ANSWER:  (a) Government Expenditure:

1. Government has to invest huge amount on public works like roads, buildings, irrigation works, etc.
2. During inflation, government should curtail (reduce) its expenditure on public works like roads, buildings, irrigation works thereby reducing the money income of the people and their demand for goods and services.

(b) Open Market Operation:

1. It consists of buying and selling of government securities and bonds in the open market by central bank.
2.  In a situation of excess demand leading to inflation, central bank sells government securities and bonds to commercial bank. With the sale of these securities, the power of commercial bank of giving loans decreases, which will control excess demand.

Q.6 Differentiate between full employment and underemployment equilibrium.
ANSWER: 

Q.7 What is meant by Margin Requirement? How does the Central Bank use this measure to control deflationary conditions in an economy?[CBSE Sample Paper 2016]
ANSWER: 

1. Business and traders get credit from commercial bank against the security of their goods. Bank never gives credit equal to the full value of the security. It always pays less value
   than the security.
2. So, the difference between the value of security and value of loan is called marginal requirement.
3. In a situation of deficient demand leading to deflation, central bank decreases marginal requirements. This encourages borrowing because it makes people get more credit against their securities.

Long Answer Type Question:

Q.1. Explain the concept of underemployment equilibrium with the help of a diagram. Show on the same diagram the additional investment expenditure required to reach full employment equilibrium.[CBSE 2004] OR
Explain the meaning of underemployment equilibrium. Explain two measures by which full employment equilibrium can be reached. [A/2013 (Set-7)]
ANSWER:

1. Underemployment equilibrium refers to a situation when equilibrium is attained i.e., aggregate demand is equal to aggregate supply below full employment level or when resources are not fully employed.
   
2.  In the above diagram full employment level of national income is attained at point E, but due to deficient demand, aggregate demand shifts downward from AD to AD0 and hew equilibrium is attained at point E1; which is below full employment level. The aggregate demand shifts downward because of the following reasons.
   (i) Decrease in household consumption demand due to fall in propensity to consume.
   (ii) Decrease in private investment demand because of fall in credit facilities.
   (iii) Decrease in public (government) expenditure.
   (iv) Decrease in export demand.
   (v) Decrease in money supply or decrease in disposable income.
3. In order to achieve full employment equilibrium deficiency of demand must be corrected through additional investment expenditure. In the diagram deficiency of AD = AB. Thus, AB amount of additional investment is required to reach the level of full employment.

Q.2 Differentiate between inflationary gap and deflationary gap. Show deflationary gap on a diagram. Can this gap exist at equilibrium level? Explain. [CBSE, 2004, AI 2013]
ANSWER:

Yes, deflationary gap can exist at equilibrium level of income. In the below figure equilibrium is attained at a equilibrium point E,, when deflationary gap is EB.

Q.3 Explain the concept of Inflationary Gap. Explain the role of Repo Rate in reducing this gap. [CBSE 2015] Or
What is meant by Repo Rate? How does the Central Bank use this measure to control inflationary conditions in an economy? [CBSE Sample Paper 2016]
ANSWER:

1. Inflationary gap is the gap showing excess of current aggregate demand over ‘aggregate supply at the level of full employment’. It is called inflationary because it leads to inflation (continuous rise in prices).
2. It can be explained with the help of following diagram:
   
3.  (i) Repo rate is the. rate at which commercial bank borrow money from the central bank for short period by selling their financial securities to the central bank.
   (ii) These securities are pledged as a security for the loans.
   (iii) It is called Repurchase rate as this involves commercial bank selling securities to RBI to borrow the money with an agreement to repurchase them at a later date and at a predetermined price.
   (iv) So, keeping securities and borrowing is repo rate.
   (v) In a situation of excess demand leading to inflation,
   • Central bank raises repo rate that discourages commercial banks in borrowing from central bank as it will increase the cost of borrowing of commercial bank.
   • It forces the commercial banks to increase their lending rates, which discourages borrowers from taking loans, which discourages investment.
   • Again high rate of interest induces households to increase their savings by restricting expenditure on consumption.
   • Thus, expenditure on investment and consumption is reduced, which will control the excess demand.

Q.4 Explain the concept of Deflationary Gap and the role of ‘Open Market Operations’ in reducing this gap.[CBSE 2015]
ANSWER:

1. Deflationary gap is the gap showing deficient of current aggregate demand over ‘aggregate supply at the level of full employment. It is called deflationary because it leads to deflation (continuous fall in prices).
2. It can be explained with the help of following diagram:
   
3. (i) Open Market Operation consists of buying and selling of government securities and bonds in the open market by central bank.
   (ii) In a situation of deficient demand leading to deflation,central bank purchases government securities and bonds from commercial bank. With the purchase of these securities, the power of commercial bank of giving loans increases, which will control deficient demand.

Q.5 What is ‘deficient demand’? Explain the role of ‘Bank Rate’ in removing it.[AI 2015]
ANSWER:

1. When in an economy, aggregate demand falls short of aggregate supply at full employment level, the demand is said to be a deficient demand.
2. It can be explained with the help of following diagram:
   
3. (i) Bank rate is the rate of interest at which central bank lends to commercial banks without any collateral (security for purpose of loan). The thing, which has to be remembered, is that central bank lends to commercial banks and not to general public.
   (ii) In a situation of deficient demand leading to deflation,
   • Central bank decreases bank rate that encourages commercial banks in borrowing from central bank as it will decrease the cost of borrowing of commercial bank.
   • Decrease in bank rate makes commercial bank to decrease their lending rates, which encourages borrowers from taking loans, which encourages investment.
   • Again low rate of interest induces households to decrease their savings by increasing expenditure on consumption.
   • Thus, expenditure on investment and consumption increase, which will control the deficient demand.

Q.6 What is ‘excess demand’? Explain the role of ‘Reverse Repo Rate’ in removing it. [AI 2015]
ANSWER:

1. When in an economy, aggregate demand exceeds “aggregate supply at full employment level”, the demand is said to be an excess demand.
2. It can be explained with the help of following diagram:
   
3. (i) Reverse Repo Rate is the rate at which the central bank (RBI) borrows money from commercial bank.
   (ii) In a situation of excess demand leading to inflation, Reverse repo rate is increased, it encourages the commercial bank to park their funds with the central bank to earn higher return on idle cash. It decreases the lending capability of commercial banks, which controls excess demand.

In This Post we are  providing Chapter-16 PROBABILITY NCERT MOST IMPORTANT QUESTIONS for Class 11 MATHS which will be beneficial for students. These solutions are updated according to 2021-22 syllabus. These MCQS  can be really helpful in the preparation of Board exams and will provide you with a brief knowledge of the chapter.

NCERT MOST IMPORTANT QUESTIONS ON PROBABILITY

Question 1.
A coin is tossed twice, what is the probability that at least one tail occurs?

Solution:
Let S is the sample space, then
S = {(H, H), (H, T), (T, H), (T, T)}
n(S) = 4
Let E be the event of getting at least one tail, then
E = {(H, T), (T, H), (T, T)}
∴ n(E) = 3
Hence, required probability P(E) = n(E)n(S) = 34

Question 2.
There are four men and six women on the city council. If one council member is selected for a committee at random, then how likely is it that it is a woman?

Solution:
Let S is the sample space, then
n (S) = 10
Let E be the event that woman is selected, then
n(E) = 6
Hence, required probability P(E) = n(E)n(S)
P(E) = 610 = 35

Question 3.
If 211 is the probability of an event A, then find what is the probability of the event is ‘not A’.

Solution:
Given that :
P(A) = 211
We know that,
P(A) + P(A¯) = 1
211 + P(A¯) = 1
P(A¯) = 1 – 211 = 11–211
P(A¯) = 911.

Question 4.
A box contain 10 red marbles, 20 blue marbles and 30 green marbles. 5 marbles are drawn from the box. What is the probability that:

1. All marbles will be blue.
2. At least one marble will be green.

Solution:
In the box, there are 10 red, 20 blue and 30 green marbles.
The No. of marbles = 10 + 20 + 30 = 60
1. Total ways of choosing 5 marbles out of 60 marbles,
n(S) = ⁶⁰C₅
Let E is the event of choosing blue marbles, then
n(E) = ²⁰C₅
Probability = n(E)n(S) = 20C560C5

2. P(At least one green marble)
= 1 – P(No green)
= 1 – 30C560C5

Question 5.
4 cards are drawn from a well shuffled deck of 52 cards. What is the probability of obtaining in card of 3 diamond and one spade?

Solution:
Let S is the sample space.
Total number of selecting 4 cards out of 52 cards, n(S) = ⁵²C₄
If E is the event obtaining card of 3 diamond and 2 spade, then
n(E) = ¹³C₃ x ¹³C₁
Probability P(E) = n(E)n(S) = 13C3×13C152C4

Question 6.
Given : P(A) = 35 and P(B) = 15. If A and B are mutually exclusive events, then find P(A or B). (NCERT)

Solution:
A and B are mutually exclusive events.
∴ P (A or B) = P(A ∪ B) = P(A) + P(B)
P(A ∪ B) = 35 + 15 = 3+15 = 45

Question 7.
In a lottery, a person choose six different natural numbers at random from 1 to 20 and if there six numbers match with the six numbers already fixed by lottery committee, he wins the prize, what is the probability of winning the prize in the game? (Hint: Order of the numbers is not important)

Solution:
Let S is the sample space, then
n(S) = ²⁰C₆
= 20×19×18×17×16×156×5×4×3×2×1 = 38760
Only one prize can be win.
∴ n(E) = 1
Hence, required probability P(E) = n(E)n(S) = 13876

Question 8.
Two dice are thrown simultaneously. Find the probability of getting a sum 9 in a single throw.

Solution:
Total number of ways in which two dice may be thrown
= 6 x 6 = 36
∴ n(S) = 36
Event of getting sum 9 is A = {(3, 6), (4, 5), (5, 4), (6, 3)}
∴ n(A) = 4
∴ Required probability P(A) = n(A)n(S) = 19

Question 9.
A bag contains 8 black, 6 white and 5 red balls. Find the probability of drawing a black or a white ball from it

Solution:
Total number of balls = 8 + 6 + 5 = 19
∴ n(S) = 19
Event A of drawing 1 black or 1 white ball
n(A) = 8 + 6 = 14
∴ n(A) = 14
∴ Required probability P(A) = n(A)n(S) = 1419

Question 10.
From a pack of well shuffled cards two cards drawn simultaneously. Find the probability that both the cards are ace.

Solution:
Total number of ways of drawing two cards out of 52
= ⁵²C₂
Number of ways drawing two ace out of 4 ace
= ⁴C₂
∴ Required Probability

Question 11.
A pair of dice are thrown. Find the probability that the sum is 9 or 11.

Solution:
Let the sample space be S, then
∴ n(S) = 36
Let E be the event that sum is 9 or 11, then
E = {(5, 4), (4, 5), (6, 3), (3, 6), (6, 5), (5, 6)}
∴ n (E) = 6
The probability of getting sum 9 or 11 is
P(E) = n(E)n(S) = 636 = 16
Hence, probability that the sum is not 9 or 11 is
P(E¯) = 1 – P(E)
= 1 – 16 = 56

Question 12

A letter is selected at random from the word ‘ASSASSINATION’. Find the probability that letter is

1. a vowel
2. a consonant

Solution:
Number of letters is 13 in which there are 6 vowels and 7 consonants.
1. Let sample space is S, then
∴ n(S) = 13
E₁ is the event of choosing a vowel, then

n(E₁) = 6
Hence, required probability P(E₁) = n(E1)n(S)
P(E₁) = 613

2. E₂ is the event of choosing a consonant, then
n(E₁) = 7
Hence, required probability P(E₂) = n(E2)n(S)

Question 13.
In class XI of a school, 40% of the students study Mathematics and 30% study Biology. 10% of the class study both Mathematics and Biology. If a student is selected at random from the class, find the probability that he will be studying Mathematics or Biology.

Solution:
Let M and B denote the students of Mathematics and Biology respectively. Then, as given:
P(M) = 40% = 40100
= P(B) = 30% = 30100
P(M ∩ 5) = 10% = 10100
∴ P(M ∪ B) = P(M) + P(B) – P(M ∩ B)
40100 + 30100 – 10100
= 60100 = 60% = 0.6

Question 14.
In an entrance test that is graded on the basis of two examinations, the probability of a randomly chosen student passing the first examination is 0.8 and the probability of passing the second examination is 0.7. The probability of passing at least one of them is 0.95. What is the probability of passing both? (NCERT)

Solution:
Let probability of passing in first examination is A and passing in the second examination is B.
P(A) = 0.8, P(B) = 0.7, P(A ∪ B) = 0.95, P(A ∩ B) = ?
We know that,
P(A ∪ B) = P(A) + P(B) – P(A ∩ B)
0.95 = 0.8 + 0.7 – P(A ∩ B)
⇒ P(A ∩ B) = 1.5 – 0.95
∴ P(A ∩ B) = 0.55.

Question 15.
Check whether the following probabilities P{A) and P(B) are consistently defined:

1. P(A) = 0.5, P(B) = 0.7, P(A ∩ B) = 0.6
2. P(A) = 0.5, P(B) = 0.4, P(A ∪ B) = 0.8.

Solution:
1. Given : P(A) = 0.5, P(B) = 0.7, P(A ∩ B) = 0.6
If P(A ∩ B) ≤ P(A) and P(A ∩ B) ≤ P(B)
Then, P(A) and P(B) are consistent.
Here

P(A) and P(B) are not consistent.