Yearly Archives: 2022

In This Post we are  providing  CHAPTER 9 SOLAR RADIATION , HEAT BALANCE AND TEMPERATURE NCERT MOST IMPORTANT QUESTION for Class 11 GEOGRAPHY 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 QUESTION ON SOLAR RADIATION , HEAT BALANCE AND TEMPERATURE

Question 1.
What is inversion of temperature? When | and in what regions does it take place?
Answer:
At times, the situations are reversed and the normal lapse rate is inverted. It is called Inversion of temperature. Inversion is usually of short duration but quite common nonetheless. A long winter night with clear skies and still air is ideal situation for inversion. The heat of the day is radiated off during the night, and by early morning hours, the earth is’ cooler than the air above. Over polar areas, temperature inversion is normal throughout the year. Surface inversion promotes stability in the lower layers of the atmosphere.

Smoke and dust particles get collected beneath the inversion layer and spread horizontally to fill the lower strata of the atmosphere. Dense fogs in mornings are common occurrences especially during winter season. This inversion commonly lasts for few7 hours until the sun comes up and beings to warm the earth. The inversion takes place in hills and mountains due to air drainage.

Question 2.
How does the energy received in upper layer of the atmosphere keep changing at different times of the year?
Answer:
The solar output received at the top of the atmosphere varies slightly in a year due to the variations in the distance between the earth and the sun. During its revolution around the sun, the earth is farthest from the sun (152 million km) on 4th July. This position of the earth is called aphelion.On 3rd January, the earth is the nearest to the sun (147 million km). This position is called perihelion. Therefore, the annual insolation received by the earth on 3rd January is slightly more than the amount received on 4th July.

However, the effect of this variation in the solar output is masked by other factors like the distribution of land and sea, and the atmospheric circulation. Hence, this variation in the solar output does not have great effect on daily weather changes on the surface of the earth.

Question 3.
How does the amount of insolation received depends on the angle of inclination of the rays?
Answer:
The amount of insolation received depends on the angle of inclination of the rays. It depends on the latitude of a place. The higher the latitude the less is the angle they make with the surface of the earth resulting in slant sunrays. The area covered by vertical rays is always less than the slant rays. If more area is covered, the energy gets distributed and the net energy received per unit area decreases. Moreover, the slant rays are required to pass through greater depth of the atmosphere resulting in more absorption, scattering and diffusion.

Question 4.
Explain about spatial distribution of insolation on the earth’s surface.
Answer:
The insolation received at the surface varies from about 320 Watt/m2 in the tropics to about 70 Watt/m2 in the poles. Maximum latitude insolation is received over the subtropical deserts, where the cloudiness is the least. Equator receives comparatively less insolation than the tropics. Generally, at the same latitude the insolation is more over the continent than over the oceans. In winter, the middle and higher latitudes receive less radiation than in summer.

Question 5.
Explain the distribution of temperature in July.
Answer:
Distribution of temperature in July

• During this period the sun shines vertically over head near the tropic of cancer. It is summer for the northern hemisphere and winters for the southern hemisphere.
• In the northern hemisphere the isotherm bends equator wards while crossing the oceans and pole wards ‘while crossing the landmass. In the southern hemisphere it is vice-versa.
• The isotherms are most irregular and zig-zig in northern hemisphere on the other hand the isotherms are relatively more regular and straight in southern hemisphere.
• Maximum temperature of about 30 degree centigrade occurs entirely in the northern hemisphere between 10° and 40° north latitude however the lowest temperature below 0° C is recorded over northern hemisphere in the central parts of green land.

Question 6.
Explain the factors affecting insolation at the surface of earth.
Answer:
The factors affecting insolation at the surface of earth are:-

1. The rotation of earth on its axis: The fact that the earth on its axis makes an angle of 6614 with the plane of it’s orbit round the sun has a greater influence on the amount of insolation received at different latitudes.

2. The angle of inclination of the sunrays: The higher the latitude the greater is the angle they make with the surface of the’earth resulting in slant sunrays. The areas covered by vertical rays is always less than the slant rays. If more areas is covered the energy gets distributed and the net energy received per unit area decreases. Thus, the slant rays are required to pass through greater depth of the atmosphere resulting in more absorption, scattering and diffusion.

3. The transparency of the atmosphere:
The atmosphere is largely transparent to the short wave solar radiation. The incoming solar radiation passes through the atmosphere before striking the earth’s surface. Within the troposphere water vapour, ozone and other gases absorb much of the near infrared radiation.

4. The configuration of land in terms of its aspect: The insolation received at the surface varies from about 320 watt/ m2 in the poles. Maximum insolation is received over the subtropical deserts, when the cfoudness is the least. Equator receives less rainfall as compared to tropics

Question 7.
Distribution of temperature in the month of July.
Answer:

• During this period the sun shines vertically over head near tropic of cancer it is the summer for northern hemisphere and winter for southern hemisphere.
• The isotherms are relatively more regular and straight in southern hemisphere.
• Maximum temperature of over 30°C occurs entirely in northern hemisphere between 10° and 40° temperature below 0° C is recorded over northern hemisphere in the central parts of Greenland.

Question 8.
Explain the distribution of temperature in January.
Answer:

1. In January the isotherms deviate to north over the ocean and to the south over the continent. This can be seen on the North Atlantic Ocean.

2. The pressure of warm ocean currents, Gulf Stream and north Atlantic drift, make the northern Atlantic Ocean warmer and the isotherms bend towards the north.

3. Over the land the temperature decreases sharply and the isotherms bend towards south in Europe.

4.  It is much pronounced in the Siberian plan. The mean January temperature along 60° E longitude is minus 20° both at 80° N and 50° N latitude. The mean monthly temperature for January is over 27° C in equatorial oceans over 24°C in the tropics and 2° C- 0° C in middle latitudes and -18° C to -48° C in Eurasian continental interior.

5. The effect of the ocean in well pronounced in southern hemisphere. Here, the isotherms are more or less parallel to latitudes and the variations in temperature is more gradual than in the northern hemisphere. The isotherm of 20°C, 10°C, and 0°C run parallel to 35°S, 45° and 60°S latitudes respectively.

Question 9.
Explain about inversion of temperature.
Answer:
At times, the situations are reversed and the normal lapse rate is inverted. It is called inversion of temperature. Inversion is usually of short duration but quite common nonetheless. A long winter night with clear skies and still air is ideal situation for inversion. The heat of the day is radiated off during the night, and by early morning hours, the earth is cooler than the air above.

Over polar areas, temperature inversion is normal throughout the year. Surface inversion promotes stability in the lower layers of the atmosphere. Smoke and dust particles get collected beneath the inversion layer and spread horizontally to fill the lower strata of the atmosphere. Dense fogs in mornings are common occurrences especially during winter season. This inversion commonly lasts for few hours until the sun comes up and beings to warm the earth. The inversion takes place in hills and mountains due to air drainage.

Question 10.
Explain the heating and the cooling mechanism of atmosphere.
Or
Discuss the process through which earth and the atmosphere system maintain heat balance.
Answer:
(a) Conduction:

• The earth after being heated by insolation transmits the heat to the atmospheric layers near to the earth in long wave form. The air in contact with the land gets heated slowly and the upper layers in contact with the lower layers also get heated.
• Conduction takes place when two bodies of unequal temperature are in contact with one another, there is a flow of energy from the warmer to cooler body. The transfer of heat continues until both the bodies attain the same temperature or the contact is broken. Conduction is important in heating the lower layers of the atmosphere.

(b) Convection:

• The air in contact with the earth rises vertically on heating in the form of currents and further transmits the heat of the atmosphere. This vertical heating of atmosphere is known as convection.
• The convection transfer of energy is confined only to the troposphere.

(c) Advection:

• The transfer of heat through horizontal movement of air is called advection. Horizontal movement of the air is relatively more important than the vertical movement.
• In tropical regions particularly in northern India during summer season local winds called ‘loo’ is the outcome of advection process.

In This Post we are  providing  CHAPTER 10 ATMOSPHERIC CIRCULATIONS AND WEATHER SYSTEMS NCERT MOST IMPORTANT QUESTION for Class 11 GEOGRAPHY 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 QUESTION ON ATMOSPHERIC CIRCULATIONS AND WEATHER SYSTEMS

Question 1.
What is a jet stream? Explain.
Answer:
The winds with a high velocity which blow at high altitude are called the jet stream. This strong current of air is located near 90° north latitude. It affects the weather patterns of the world. High flying planes use these as super tailwinds to save time and fuel.

Question 2.
Describe the local winds in brief.
Answer:
Winds having special characteristics under local conditions are known as local winds.

1. Hot winds: Chinook in Canada and USA, foehn in Switzerland.
2. Dry winds: Sirocco in south Europe, Khanzim in Egypt, Hermatton in West Africa, Simoon of Arabia, Santa Anna of California, Zenda of Argentina.
3. Cold winds: Boro and Mistral in Southern Europe, Pampero in Argentina, Buran in Siberia.

Question 3.
Write a short note on ‘doldrums’.
Answer:
The doldrum is an equatorial low-pressure belt between 5°N to 5°S latitudes. It is known as the-belt of calm. The air is constantly heated due to the high temperature. The air expands and rises as convection currents. There are no surface winds. Sailing ships often found them becalmed in this belt due to the absence of backing winds.

Question 4.
What is the importance of air mass?
Answer:
Air mass is important for climatological study. Air masses are related to atmospheric disturbances, cyclones, storms, and fronts.

• The distribution and location of air provide an essential understanding of regional climate.
• Air masses transfer heat from lower latitude to higher latitudes.
• Atmosphericdisturbancesdevelopalongfrontsofdifferentairmasses.
• Air masses are associated with particular types of wind belts and determine the weather characteristics.

Question 5.
What do you understand by valley breeze?
Answer:
The valley breeze occurs during day time. Due to insolation, the valley bottom gets heated. The hot air becomes light and ascends towards the upper slopes. It is known as the valley breeze.

Fig. 10.3: Slopes heated by insolation

Question 6.
Distinguish between:
1. planetary and periodic winds,
2. the sea breeze and land breeze.
Answer:
1. Planetary and periodic winds:
Planetary winds are related to the general circulatory pattern of winds on the rotating earth’s surface. These winds constitute the large-scale motion of the atmosphere under the influence of pressure gradients. They ignore seasonal heating and land-water contrast on the earth’s surface. They are also called permanent or primary wind system of the earth’s surface and comprise trade winds, westerlies, and polar easterlies. These winds blow constantly in a particular direction throughout the year.

Fig. 10.4: Planetary winds

The winds that change their direction periodically with the change in season are called periodic or secondary winds. Monsoon, air masses and fronts, cyclones and anticyclones, land and sea breezes, and mountain and valley breezes are the wind systems that periodically change their courses diurnally or seasonally.

2. Land and sea breezes:
Daily temperature contacts between land and water produce a small diurnal reversal of winds called land and sea breezes. Both are basically caused by differential heating of land and sea.

During the day, the land gets heated up much faster than the sea. The sea remains comparatively cool with higher pressure, so the sea breeze blows in from the sea to land during the day. Its speed is between 5-20 miles/hour and it is generally stronger in tropical than temperate regions.

Its influence does not normally exceed 15 miles from the coast. It is most deeply felt when one stands facing the sea in a coastal area.

At night, the reverse takes place. As the land cools down much faster than the sea, the cold and heavy air produces a region of local high pressure. The sea conserves its heat and remains quite warm. Its pressure is comparatively low. A land breeze thus blows out from land to sea.

Fishermen in the tropics often take advantage of the outgoing land breeze and sail out with it.

Question 7.
Describe the global pattern of the distribution of pressure.
Answer:
The horizontal distribution of pressure, or its global pattern in general, presents an alternate belt of low and high-pressure areas.

There is an inverse relationship between pressure and temperature. The equatorial region having high temperature has low pressure, while the polar regions with low temperature have high pressure. These pressure belts are thermally induced. Logically, there should have been a gradual increase in pressure from the equator towards the poles.

Fig. Pressure belts of the world (See fig.9.1)

There are two intermediate zones of subtropical highs in the vicinity of 30°N and S and two sub-polar lows in the vicinity of 60°N and S. The dynamic control, viz., pressure gradient force, rotation of the earth, are responsible for the formation of these pressure belts.

Thus there are seven pressure belts:

1. An equatorial trough of low pressure.
2. Sub-tropical high-pressure belt (Northern hemisphere)
3. Sub-polar low-pressure belt (Northern hemisphere)
4. Sub-polar low-pressure belt (Southern hemisphere)
5. Sub-tropical high-pressure belt (Southern hemisphere)
6. Polar high (Northern hemisphere)
7. Polar high (Southern hemisphere)

Question 8.
Discuss the seasonal variations in the pressure distribution over the earth’s surface.
Answer:
Despite a broad generalized pattern of pressure distribution on the earth, pressure conditions vary considerably on the basis of prevailing weather conditions in different parts of the world. The horizontal distribution of pressure on the earth’s surface is shown by isobar. Just as there is a daily range of temperature on the surface of tire earth, so there is the diurnal rhythm of pressure.

The direction and rate of change in pressure are called pressure gradient. It is at right angles to isobars, just as the slope of the land surface is at right angles to contour, lines. The rate of change or steepness of the gradient is shown by the spacing of isobars. Closely spacing isobars show’ steep pressure gradient, and widely spaced isobars show’ gentle gradient.

The zonal distribution of pressure is modified by continents and oceans, in summer, the relatively hot continents intensify the low-pressure cells and weaken or destroy high-pressure cells. In a similar manner, the corresponding cooler oceans weaken the low-pressure cells and the high-pressure cells. In winter the situation is reversed. ,

Fig. 10.6: Horizontal distribution of pressure and winds

Question 9.
What are cyclones? Describe the various types of cyclones.
Answer:
Cyclones constitute the most fundamental and climatically the most significant atmospheric disturbances affecting the weather. On the basis of the areas of their origin, they are classified into two types: temperate and tropical.

Temperate cyclones: Temperate1 cyclones are concentrated in the middle latitudes between 35° and 65° in both hemispheres. They are generally extensive having a vertical thickness ranging from 9 to 11 km. and a diameter of about 1,000 km. It is just like a spearhead, having the shape of an upturned ‘V’. The approaching temperate cyclones are noticed by the appearance of dark clouds in the background of white clouds.

According to polar front theory, the highs and lows of westerly wind belts result from the interactions and alteration of two contrasting types of air masses, one in the polar region and the other in the subtropics. Cold air from highs moves toward the equator and is deflected westward, forming the northeast and southeast polar winds. Warmer air from the subtropical highs moves toward the poles and by an eastward deflection from the westerly winds.

Fig. 10.7: Temperate cyclones

As soon as the cyclone approaches, there is drizzle followed by heavy rainfall. The velocity of the wind increases. On the approach of the warm front, the fall in the pressure stops, and the sky becomes clear. This gives the clue that the center of the cyclones has reached. Immediately after this, the temperature begins to fall and the sky becomes cloudy and raining again. This indicates the approach of a cold front.

Tropical cyclones: These are violent storms that originate over tropical seas and move over the coastal areas bringing about large-scale destruction caused by violent winds, very heavy rainfall, and storm surges. They are known as cyclones in the Indian ocean, hurricanes in the Atlantic, typhoons in the western Pacific and South China sea, and willy-willies in west Australia. The conditions favorable for the formation and intensification of tropical storms are:

• Large sea surface with a temperature higher than 27°C.
• Presence of the Coriolis force.
• Small variations in the vertical wind speed.
• A pre-existing weak low-pressure area or low level cyclonic
  circulation.
• Upper divergence above the sea level system.

The cyclone creates stone surges and they inundate the coastland. Over the Indian sea, the cyclonic storms occur in the pre-monsoon

Question 10.
Define and describe the fronts.
Answer:
The contact line between air masses of different properties is called a front. A cold front develops where the cold air mass moves under warm air mass and lifts it up. On the other hand, the trailing edge of a cold air mass that is followed by warm air is called a warm front. In each case, precipitation is likely to occur because warm air is rising over the cold air. Thus duration and intensity of precipitation along the few from.s are quite different. The cold front is steep and produces showery and sometimes violet precipitation for a longer period of time. If the cold front moves faster than the warm front in such a trap, part or all the pocket of warm air may be lifted from the surface, thus producing air occluded front. Often exculpation of the air masses lose earlier characters and form new fronts.

In This Post we are  providing  CHAPTER 11 WATER IN ATMOSPHERE NCERT MOST IMPORTANT QUESTION for Class 11 GEOGRAPHY 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 QUESTION ON WATER IN ATMOSPHERE

Question 1.
What is convectional rain?
Answer:
Convectional Rain: The air on being heated, becomes light and rises up in convection currents. As it rises, it expands and loses heat and consequently, condensation takes place and cumulous clouds are formed. With thunder and lightening, heavy rainfall takes place but this does not last for long.

Question 2.
What factors influence the process of condensation?
Answer:
Condensation is influenced by the volume of air, temperature, pressure and humidity. Condensation takes place:

• when the temperature of the air is reduced to dew point with its volume remaining constant;
• when both the volume and the temperature are reduced;
• when moisture is added to the air through evaporation.

Question 3 .
Name and define three important types of rainfall.
Answer:
On the basis of origin, rainfall may be classified into three main types:

1. The convectional rain
2. Orographic or relief rain and
3. Cyclonic or frontal rainfall

1. Convectional rain: The air on being heated, becomes light and rises up in convection currents. As it rises, it expands and loses heat and consequently, condensation takes place and cumulous clouds are formed. With thunder and lightening, heavy rainfall takes place but this does not last for long.
Such rain is common in the summer or in the hotter part of the day. It is very common in the equatorial regions and interior parts of the continents, particularly in the northern hemisphere.

2. Orographic rain: When the saturated air mass comes across a mountain, it is forced to ascend and as it rises, it expands; the temperature falls, and the moisture is condensed. In this sort of rain the windward slopes receive greater rainfall. After giving rain on the windward side, when these winds reach the other slope, they descend, and their temperature rises. Then their capacity to take in moisture increases and hence, these leeward slopes remain rainless and dry. The area situated on the leeward side, which gets less rainfall is known as the rain-shadow area. It is also known as the relief rain.

3. Cyclonic rainfall: These rains take place in low pressure areas where air moves from low pressure area to high pressure are a and this movement brings rainfall.

Question 4.
Explain the process of evaporation.
Answer:
Evaporation is a process by which water is transformed from liquid to gaseous state. Heat is the main cause for evaporation. The temperature at which the water starts evaporating is referred to as the latent heat of vapourisation. Increase in temperature increases water absorption and retention capacity of the given parcel of air. Similarly, if the moisture content is low, air has a potentiality of absorbing and retaining moisture. Movement of air replaces the saturated layer with the unsaturated layer. Hence, the greater the movement of air, the greater is the evaporation.

Question 5.
Explain cyclonic rain.
Answer:
Air expands when heated and gets compressed when cooled. This results in variations in the atmospheric pressure. The result is that it causes the movement of air from high pressure to low pressure, setting the air in motion. Air in horizontal motion is wind. Atmospheric pressure also determines when the air will rise or sink. The wind redistributes the heat and moisture across the planet, thereby, maintaining a constant temperature for the planet as a whole. The vertical rising of moist air cools it down to form the clouds and bring precipitation. It is called cyclonic rain.

Question 6.
Differentiate between
Answer:
(i) Precipitation and Condensation.

Basis	Precipitation	Condensation
Meaning	After the condensation of water vapour, the release of moisture is known as precipitation. This may take place in liquid or solid form.	The transformation of water vapour into water is called condensation. Condensation is caused by the loss of heat.
Sequence	Precipitation takes place after condensation.	Condensation takes place before precipitation.
Forms	It may take form of rainfall, snowfall, hailstorms, sleet etc.	It may take form of dew, smog, clouds, fog and mist etc.

(ii) Absolute humidity and Relative humidity.

Basis	Absolute Humidity	Relative Humidity
Meaning	The actual amount of the water vapour present in the atmosphere is known as the absolute humidity.	The percentage of moisture present in the atmosphere as compared to its full capacity at a given temperature is known as the relative humidity.
Unit	It is the weight of water vapour per unit volume of air and is expressed in terms of grams per cubic metre.	It is measured in percentage and hence is unit free.

(iii) Convection rain and Relief rain.

Basis	Convection Rain	Relief Rain
Meaning	The, air on being heated, becomes light and rises up in convection currents. As it rises, it expands and loses heat and consequently, condensation takes place and cumulous clouds are formed. With thunder and lightening, heavy rainfall takes place but this does not last for long.	When the saturated air mass comes across a mountain, it is forced to ascend and as it rises, it expands; the temperature falls, and the moisture is condensed. In this sort of rain is that the windward slopes receive greater rainfall. After giving rain on the windward side, when these winds reach the other slope, they descend, and their temperature rises. Then their capacity to take in moisture increases and hence, these leeward slopes remain rainless and dry.
Timing	Such rain is common in the summer or in the hotter part of the day.	Such rain is common in winters.
Prevalent	It is very common in the equatorial regions and interior parts of the continents, particularly in the northern hemisphere.	It is very common in terrestrial regions.

(iv) Fog and Mist.

Basis	Fog	Mist
Meaning	Fogs are drier than mist.	The mist contains more moisture than the fog.
Prevalent	They are prevalent where warm currents of air come in contact with cold currents.	Mists are frequent over mountains as the warm air rising up the slopes meets a cold surface.
Structure	In mist each nuclei contains a thicker layer of moisture.	Fogs are mini clouds in which condensation takes place around nuclei provided by the dust, smoke, and the salt particles.

Question 7.
Explain about condensation in detail.
Answer:
1. Meaning: The transformation of water vapour into water is called condensation. Cause: Condensation is caused by the loss of heat.

2. Sublimation: When moist air is cooled, it may reach a level when its capacity to hold water vapour ceases. Then, the excess water vapour condenses into liquid form. If it directly condenses into solid form, it is known as sublimation.

3. Process: In free air, condensation results from cooling around very small particles termed as hygroscopic condensation nuclei. Particles of dust, smoke and salt from the ocean are particularly good nuclei because they absorb water. Condensation also takes place when the moist air comes in contact with some colder object and it may also take place when the temperature is close to the dew point. Condensation, therefore, depends upon the amount of cooling and the relative humidity of the air.

Factors affecting condensation:

• When the temperature of the air is reduced to dew point with its volume remaining constant;
• When both the volume and the temperature are reduced;
• When moisture is added to the air through evaporation.

However, the most favourable condition for condensation is the decrease in air temperature. After condensation the water vapour or the moisture in the atmosphere takes form of dew, frost, fog and clouds.

Question 8.
Explain about fog and mist.
Answer:
When the temperature of an air mass containing a large quantity of water vapour falls all of a sudden, condensation takes place within itself on fine dust particles. So, the fog is a cloud with its base at or very near to the ground.

• Because of the fog and mist, the visibility becomes poor to zero. In urban and industrial centres smoke provides plenty of nuclei which help in the formation of fog and mist.
• Such a condition when fog is mixed with smoke, is described as smog.
• The only difference between the mist and fog is that mist contains more moisture than the fog.
• In mist each nuceli contains a thicker layer of moisture. Mists are frequent over mountains as the warm air rises up the slopes and meets a cold surface.
• Fogs are drier than mist and they are prevalent where warm currents of air come in contact with cold currents. Fogs are mini clouds in which condensation takes place around nuclei provided by the dust, smoke, and the salt particles.

Question 9.
On the basis of rainfall received, in how many groups can we classify the world?
Answer:
On the basis of rainfall received, we can classify the world into five groups.

1. The equatorial belt, the windward slopes of the mountains along the western coasts in the cool temperate zone and the coastal areas of the monsoon land receive heavy rainfall of over 200 cm per annum.
2. Interior continental areas receive moderate rainfall varying from 100 – 200 cm per annum.
3. The coastal areas of the continents receive moderate amount of rainfall.
4. The central parts of the tropical land and the eastern and interior parts of the temperate lands receive rainfall varying between 50-100 cm per annum.
5. Areas lying in the rain shadow zone of the interior of the continents and high latitudes receive very low rainfall-less than 50 cm per annum.

Question 10.
Use a diagram to explain the process of evaporation.
Answer:
Evaporation is a process by which water is transformed from liquid to gaseous state. Heat is the main cause for evaporation. Movement of air replaces the saturated layer with the unsaturated layer. Hence, the greater the movement of air, the greater is the evaporation.

In This Post we are  providing  CHAPTER 8 COMPOSITION AND STRUCTURE OF ATMOSPHERE NCERT MOST IMPORTANT QUESTION for Class 11 GEOGRAPHY 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 QUESTION ON COMPOSITION AND STRUCTURE OF ATMOSPHERE

Question 1.
Why are the vapour and dust particles important variables of weather and climate?
Answer:
The water vapour and dust particles are important variables of weather and climate because they are the source of all forms of condensation and principal absorbers of heat received from the sun or radiated from the earth. Besides, they affect the stability of the atmosphere.

Question 2.
What is meant by a normal lapse rate?
Answer:
The temperature decreases with altitude because the atmosphere is heated more by the heat radiated from the earth’s surface. Wanner air lying under the cooler air goes up or turns downward. In this layer, the temperature decreases vertically at a rate of 0.65°C per 100 metres. It is called the normal lapse rate.

Question 3.
What is homosphere?
Answer:
The atmospheric layer up to an altitude of 90 km. above the surface of the earth is generally called homosphere. It is uniform in term of these major gases – nitrogen, oxygen and argon. In addition, it also contains some rare gases like neon, krypton and xenon.

Question 4.
Name the gases and other materials which compose the atmosphere.
Answer:
Nitrogen, oxygen and argon are the most important gases of the atmosphere. In addition, it contains gases like carbon dioxide, neon, helium, ozone, hydrogen, methane, krypton and xenon. Besides, there are also present huge amounts of solid and liquid particles collectively called aerosols.

Question 5.
Discuss the properties of nitrogen gas.
Answer:
Nitrogen is the most abundant gas of the atmosphere. By volume, it constitutes 78.8% of the total gases present in the atmosphere. Nitrogen does not easily enter into chemical union with other substances but gets fixed into the soil. It serves mainly as diluent or dissolver. It regulates combustion.

Question 6.
Distinguish between troposphere and stratosphere.
Answer:

Troposphere	Stratosphere
(1) It is the lowermost layer of the atmosphere.	(1) It is the second layer of the atmosphere above the earth.
(2) Its height varies from 10-18 km. at the equator.	(2) Its height is up to 50 km.
(3) Temperature decreases at the rate of 1 °C per 165 metres in this layer.	(3) In this layer temperature is very low and fairly constant.
(4) It is the zone of convection currents of the atmosphere.	(4) It is a zone of non-convection currents of the atmosphere.
(5) Water vapour, dust particles, clouds are found in this layer.	(5) There is no water vapour but dust particles and clouds are found.
(6) Atmospheric processes occur in this layer.	(6) This zone is free from atmospheric disturbances.

Question 7.
What is the difference between condensation and precipitation?
Answer:
Condensation is the physical process of the transition of a substance from the vapour to the liquid state, e.g., as a result of cooling or increase of pressure. It occurs in the atmosphere when the air is saturated or when it is cool. Thus, the change of state of the moisture from invisible water vapour to visible liquid (water) or solid (ice or snow ) state is known n as condensation. It is opposite of evaporation.

Precipitation, on the other hand, means ‘throwing down of moisture’. Continuous condensation in the body of the air helps the water droplets to grow in size so that the resistance of the air fails to keep them suspended. In such cases, only an ascending air current can keep them floating in the air. In the absence of such a current, the products of condensation begin to fall on the earth’s surface. The process whereby the water vapour first condenses in the air and then falls on to the earth is called precipitation.

Question 8.
Discuss the principal elements of weather and climate and the major climatic controls.
Answer:
The principal elements of weather and climate are temperature precipitation, moisture, pressure and winds. These are called elements because they are the ingredients out of which various weather and climate types are compounded. The temperature and precipitation are the main basic elements to which pressure, winds and other elements are related.

Temperature expresses the intensity of heat. Practically all the heat energy on the earth is the result of insulation or the increasing solar radiation. Unequal distribution of temperature over the earth’s surface causes differences in atmospheric pressure, which causes winds.

Higher the temperature, the greater is the capacity’ of air to hold moisture on cooling. The air is not able to retain all the moisture it gathers while warm. This leads to condensation and precipitation.

Thus, the temperature is the basic element on which other elements of climate depend.

The climatic controls are :
Latitude (or sun), distribution of land and water, the great semi¬permanent high and low-pressure belts, winds, altitude, mountain barriers, ocean currents and storms of various kinds.

Question 9.
Define the atmosphere. Explain its importance to human life.
Answer:
The atmosphere is a mixture of air and various gases which envelopes the earth all around. It represents the gaseous realm of the earth. It is held to the earth by the force of gravity.

Importance of atmosphere:

1. It contains gases like oxygen (essential for breathing) for man and animals and carbon dioxide for plants.
2. By trapping the heat, it acts as a greenhouse. It keeps the earth
   warm.
3. One of its layer, the ionosphere, reflects radio waves back to the earth and makes radio communication possible.
4. It protects us from the deadly cosmic rays and meteors which are continuously showered on the earth from outer space.
5. All the weather phenomenon take place in the atmosphere. Presence of water vapour in the atmosphere brings many changes such as condensation and precipitation. These processes influence the human life, plants and animals.
6. It absorbs ultraviolet rays.
7. It acts as an air conditioner by moderating the extremes of heat ‘ and cold.
8. It is a storehouse of water vapour.

Question 10.
Discuss the proportion of the constituent gases of the atmosphere.
Answer:
The atmosphere is a mixture of various gases. It includes :
Nitrogen (N,), Oxygen (O,), Argon (Ar), Carbon dioxide (CO,), Neon (Ne), Helium (He), Ozone (O,), Hydrogen (H), Methane (CH4), Krypton (Kr) and Xenon (Xe).

Nitrogen (N2): It is a colourless, odourless gas, the main constituent (i.e. 78.8% by volume) of the atmosphere. It is an essential constituent of living organisms. It is an important element for plants.

Oxygen (O,): Constitutes 20.94% of the total volume of the atmosphere. It is the second most abundant gas. It is essential to plant and animal life.

Argon (Ar): It constitutes one per cent volume of the total atmosphere. It is an inert gas, does not take part in any chemical reaction.

Carbon dioxide: It constitutes a very small amount (0.03%). It is an important gas in the atmospheric process. It can absorb heat and thus allows the lower atmosphere to be warmed up by heat radiation from the sun and from the earth’s surface. Green plants in the process of photosynthesis utilise carbon dioxide from the atmosphere.

Neon (Ne): Neon is an inert gaseous element occurring in’ trivial quantities (0.0018%) in the atmosphere.

Helium (He): It exists primarily in the sun’s atmosphere. It is an inert element of the atmosphere.

Ozone (03): It is an allotropic form of oxygen (02). Its main concentration lies between 20 to 25 km. from the earth’s surface.

Hydrogen (H): It is the lightest element. It is gaseous and inflammable. It is used in many chemical processes.

NCERT MCQ ON Balance of Payment:

Q1. Balance of Payments of a country is a statement that records:-

a) Sources of Foreign Exchange
b) Uses of Foreign Exchange
c) Both a) and b)
d) None of the above

Ans:- c)
Explanation:- Balance of Payments is an accounting statement that records the foreign exchange transactions of a country with the rest of the world

Q2. The categories of transactions that are included in current account of Balance of Payments are:-

a) Exports and imports of goods
b) (a) + Exports and Imports of services
c) (b) + Income from and to abroad
d) (c) + Transfers from and to abroad

Ans – d)
Explanation:- Current Account of BoP records 1) export and imports of goods, services, income from and to abroad, unilateral transfers from and to abroad

Q3. Balance of Trade equals:-

a) Exports less imports
b) Exports of goods less imports of goods
c) Exports of services less imports of services
d) None of the aboveShow Answer

Ans – b)
Explanation:- Balance of Trade is the part of Current account of BoP. It is the differnce between Export and Import of physical goods

Q4. The categories of transactions that are included in the capital account of the Balance of Payments are:-

a) Investments from and to abroad
b) Borrowings and lendings from and to abroad
c) Changes in foreign exchange reserves
d) All the above

Ans – d)
Explanation:- Capital account of BoP records the financial transactions of a country in foreign exchange with the rest of the world that changes assets and liabilities status of a country. It includes three transactions. 1) Investments from and to abroad, 2) Borrowings and lendings from and to abroad, 3) Changes in foreign exchange reserves.

Q5. The measurement of Balance of Payments deficit is based on:-

a) Autonomous transactions
b) Accommodating transactions
c) Current account transactions
d) Capital account transactions

Ans – a)
Explanation:- Autonomous transactions are done for profit motive. Such transactions are the main cause of deficit in BoP.

Q6. Choose the correct statement from given below:

a) Balance of trade records the exports and imports of invisible items.
b) A surplus in BoT can rectify the deficit in Bop.
c) Accommodating items are only recorded in the capital account of the BOP.
d) Import of machinery will be recorded in the capital account of BoP.

Ans – c)
Explanation:- Accommodating transactionsa are only recorded in Capital Account. Main motive of such transactions are to settle the surplus and deficit of BoP due to autonomous transactions.

Q7.Choose the correct statement from given below.

a) Balance of Trade is a component of the capital account of Balance of Payments.
b) Floating exchange rate is used to stabilize the price of foreign currency.
c) Increase in the supply of foreign exchange results in a fall in its price
d) Rise in the exchange rate leads to the revaluation of the currency.

Ans – c)
Explanation:- Higher is the supply of foreign exchange, lesser is the foreign exchange rate.

Q8. Current accounts records all payments to rest of the world as_________and all receipts from rest of the world as______

a) Credit, Debit
b) Debit, Credit
c) Debit, Debit
d) Credit, CreditShow Answer

Ans – b)
Explanation:- Foreign exchange inflow is recorded on the credit side. The outflow of foreign exchange is recorded at the debit side of the BoP.

Q9. Balance on invisible trade is equal to

a) Export of goods – Import of goods
b) Export of services – Import of services
c) Import of goods – Export of goods
d) Import of services – Export of goods

Ans – b)
Explanation:- Invisible trade means trade of intangible goods like services

Q10. If value of visible exports is greater than the value of invisible imports, the balance relates to

a) Current account Bop
b) Trade Deficit
c) Capital account BoP
d) Can’t be determinedr

Ans – d)
Explanation:- Only visible exports are compared with visible imports and invisible exports are compared to invisible imports.

Q11. Balance of trade is a__________concept as compared to balance of payments.

a) narrower
b) broader
c) similar
d) None of the above

Ans – a)

Explanation:- Balance of trade is the difference between exports and imports of visible goods. It is just a part of current account

Q12. If trade deficit is ₹ 1500 crores and import of goods are ₹ 3500 crores, value of export of goods will be ₹ 2000 crores?

a) True
b) False
c) Partially true
d) Can’t be predicted

Ans – a)

Explanation:- Trade deficit = Imports of goods – Exports of goods

Q13. Trade deficit refers to the situation where

a) Export of goods is more than the import of goods
b) export of goods is less than the import of goods
c) export of services is more than the import of services
d) export of services is less than the import of services

Ans – b)

Explanation:- When exports of goods is less than the imports of goods. it is the situation of Trade Deficit.

Q14. Uni-lateral transfers are included in

a) current account Bop
b) capital account Bop
c) Both a) and b)
d) None of these

Ans – a)

Explanation:- Unilateral transfers are the part of invisible sections of Current account of BoP.

Q15. An Indian real estate company received rent from google in New York. This transaction would be recorded on____________side of_____________account.

a) credit, current
b) debit, capital
c) credit, capital
d) debit, current

Ans – a)

Explanation:- It is an income out of Investment. It is recorded as income receipts at credit side under invisible trade in current account

Q16. A company located in India receives a loan from a company located abroad. How is this
transaction recorded in India’s Balance of Payments Account?

a) Credit side of current account
b) Debit side of current account
c) Credit side of Capital account
d) Debit side of Capital account

Ans – c)

Explanation:- It is financial transaction and increases the liabilities

Q17. An Indian Company located in India invests in a company located abroad. This transaction is entered in India’s Balance of Payments Account on:-

a) Credit side of current account
b) Debit side of current account
c) Credit side of Capital account
d) Debit side of Capital account

Ans – d)

Explanation:- It is financial transaction and increases the assets of a country in rest of the world and results in outflow of foreign exchange

Q18. Foreign Exchange Transactions which are independent of other transactions in the Balance
of Payments Account are called:

a) Current transactions
b) Capital transactions
c) Autonomous transactions
d) Accommodating transactions

Ans – c)

Explanation:- Autonomous transactions are the transactions that are not influenced by other foreign exchange transactions. For example an Indian company wants to invest in USA rest state market.

Q19. Foreign Exchange Transactions dependent on other Foreign Exchange Transactions are called:

a) Current account transactions
b) Capital account transactions
c) Autonomous transactions
d) Accommodating transactions

Ans – d)

Explanation:- Accommodating transactions are those that are undertaken as a consequence of the autonomous transactions

Q20. Which of the following statements is not true?

a) Borrowings from the Asia Development Bank by the government is an accommodating
transaction.
b) Loans given to Sri Lanka by the government are an accommodating transaction.
c) Buying of machinery from Japan is an accommodating transaction
d) Borrowing from the public is an accommodating transaction.

Ans – c)

Explanation:- Autonomous items refers to those Balance of Payment (BoP0 transactions which are undertaken for profit.

Q21. Who out of the following is included in “Residents” in BoP transactions?

a) Firms
b) Foreign military personnel
c) Government agencies
d) Individuals

Ans – a),c),d)

Explanation:- Here residents means normal residents who has economic interest in the country

Q22. An accounting statement that provides a systematic record of all the economic transactions, between residents of a country and the rest of the world is________

a) Balance of Payments
b) Balance of Trade
c) Government Budget
d) None of these

Ans – a)

Explanation:- BoP is the accounting statement that records the foreign exchange transactions of a country with the rest of the world.

Q23. Balance of Payments is a___________Concept.

a) Stock
b) Flow
c) Both a) and b)
d) Neither a) nor b)

Ans – b)

Explanation:- BoP is prepared for a fiscal (accounting) year for 12 months.

Q24. Inflow of foreign exchange is recorded on the_________side.

a) Credit
b) Debit
c) Either a) or b)
d) Neither a) nor b)

Ans – a),c),d)

Explanation:- Credit side of BoP records the inflow of foreign exchagne.

Q25. When receipts of foreign exchange are more than payments of foreign exchange, BOP is:

a) Balanced
b) Surplus
c) Deficit
d) None of these

Ans – b),c),d)

Explanation:- When receipts of foreign exchange are more than payments. BoP results in surplus.

Q26. Unilateral Transfers are also known as:

a) Bilateral Transfers
b) One-way Transfers
c) Unrequited Transfers
d) Neither a) nor b)

Ans – b)

Explanation:- Unilateral transfers are one way transactions. where one person does not receive anyting in return from another person.

Q27. Balance on ‘Balance of Trade’ can be:

a) Surplus
b) Balanced
c) Deficit
d) Either a) or b) or c)

Ans – d)

Explanation:- Balance of trade is the difference between exports of goods and imports of goods. exports can be more, less and equal to imports of goods

Q28. Which of the following is a component of the Balance of Payment?

a) Current Account
b) Capital Account
c) Nominal Account
d) Real Account

Ans – a),b)

Explanation:-

Q29. Export and import of goods is also known as:

a) Indivisible Trade
b) Visible Trade
c) One-sided Transactions
d) Unrequited transfers

Ans – b)

Explanation:-

Q30. __________refers to the difference between exports and imports of visible items.

a) Balance of Payments
b) Balance of Trade
c) Both a) and b)
d) Neither a) nor b)

Ans – b)

Q31. Autonomous transactions take place on

a) Real Account
b) Capital Account
c) Current Account
d) None of these

Ans – b), c)

Explanation:-

Q32. ____________transactions are undertaken to cover the deficit or surplus in autonomous transactions.

a) current account
b) current account
c) Accommodating
d) None of these

Ans – c)

Explanation:-

Q33. ________is the difference between value of goods sold to the rest of the world and value of goods imported from rest of the world.

a) Balance of Payment
b) Balance of trade
c) Balance of current account
d) Balance of capital account

Ans – b)

Explanation:-

Q34. Gifts and remittances to abroad are recorded on the:

a) Credit side of current Account
b) Debit side of Capital Account
c) Debit side of current Account
d) Credi side of Capital Account

Ans – c)

Q35. Export of the Machinery recorded on the:

a) Debit side of Current Account
b) Credit side of Current Account
c) Credit side of Capital Account
d) Debit side of capital Account

Ans – b)

Q36. Surplus in BoP arises when

a) Autonomous Payments > Autonomous Receipts
b) Accommodating Receipts > Accommodating Payments
c) Accommodating Payments > Accommodating Receipts
d) Autonomous Receipts > Autonomous Payments

Ans – d)

Q37. Balance of Trade is also known as:

a) Balance of Visible Trade
b) Balance of Payments
c) Trade Balance
d) None of these

Ans – a)

Explanation:-

Q38. Import of Machinery is recorded in the_________Account and ‘Borrowings from abroad’ is recorded in the______Account.

a) Current, Capital
b) Capital, Current
c) Capital, Capital
d) Current, Current

Ans – a)

Explanation:-

Q39. Foreign Exchange transactions are dependent on other foreign exchange transactions are called:

a) Current Account Transactions
b) Capital Account Transactions
c) Autonomous Transactions
d) Accommodating Transaction

Ans – d)

Explanation:-

Q40. Foreign Exchange transactions which are independent of other transactions in the Balance of Payments Account are called:

a) Current Transactions
b) Capital Transactions
c) Autonomous Transactions
d) Accommodating Transactions

Ans – c)

NCERT MCQ ON I Excess Demand and Deficient Demand:

Q1._ is exercised through discussions, letters, and speeches to banks:

a) Moral suasion
b) Selective Credit Controls
c) Margin Requirements
d) Open Market Operations

Ans – a)

Q2.Which of the following is not the reason for excess demand?

a) Fall in the propensity to consume
b) Reduction in taxes
c) Decrease in investments
d) Deficit Financing

Ans – a),

Q3.Increase in cash reserve ratio will lead to:

a) Fall in Aggregate Demand
b) Rise in Aggregate Demand
c) No change in Aggregate Demand
d) Reduces credit creating power of Commercial banks

Ans – a), d)

Q4.The gap by which actual aggregate demand exceeds the aggregate demand required to establish full
employment equilibrium is known as _ .

a) Deficient Demand
b) Deflationary gap
c) Inflationary gap
d) Excess Demand

Ans – c)

Q5.“Change in Government Spending” is a part of:

a) Monetary Policy
b) Fiscal Policy
c) Either a) or b)
d) Neither a) nor b)

Ans – b)

Q6.__ refers to the situation when aggregate supply falls showt of aggregate demand
corresponding to full employment level of output in the economy.

a) Deficient Demand
b) Excess Demand
c) Inflationary Gap
d) Deflationary gap

Ans – b)

Q7.Excess demand leads to:

a) Increase in the level of employment
b) Decrease in the level of employemnt
c) No change in the level of employment
d) Increase in Price level

Ans – c), d)

Q8.Deficient Demand indicates:

a) Under employment equilibrium
b) Over full employment equilibrium
c) Full employment equilibrium
d) None of these

Ans – a)

Q9.Monetary Policy is the policy of _ to control money supply and credit creation in the
economy.

a) Central Government
b) Central Bank
c) Both a) and b)
d) None of these

Ans – b)

Q10.During excess demand, central bank __ the margin.

a) Decreases
b) Increases
c) Removes
d) Does not change

Ans – b)

Q11.If an economy is to control recession like most of the Euro Zone nations, which of the following
can be appropriate:

a) Reducing Repo Rate
b) Reducing CRR
c) Both a) and b)
d) None of a) and b)

Ans – c)

Q12.Aggregate demand can be increased by:

a) increasing bank rate
b) selling government securities by Reserve Bank of India
c) increasing cash reserve ratio
d) none of the above

Ans – d)

Q13.The monetary policy generally targets to ensure _ .

a) Price stability in the economy
b) Employment generation in the country
c) Stable foreign relations
d) Greater tax collections for the government

Ans – a)

Q14.Excess Demand can be controlled through:

a) Monetary Policy
b) Fiscal Policy
c) Both a) and b)
d) Neither a) nor b)

Ans – c)

Q15.An economy is at full employment and AD is greater than AS, what will be the impact on price level
in such an economy?

a) Rise
b) Fall
c) No change
d) Both rise and fall

Ans – a)

Q16.Which of the following can be used to correct inflationary gap under Monetary Policy?

a) Increase in Taxation
b) Reduce availability of credit
c) Cut in Government Expenditure
d) None of these

Ans – b)

Q17.Deficient Demand leads to:

a) Decrease in Planned Output
b) Fall in General Prices
c) Both a) and b)
d) Rise in Employment Level

Ans – c)

Q18.During deflation, it is advisable to:

a) Lower the bank rate and purchase of securities in the open market
b) Increase the bank rate and purchase of securities in the open market
c) Lower the bank rate and sale of securities in the open market
d) Increase the bank rate and sale of securities in the open market

Ans – a)

NCERT MCQ ON Aggregate Demand and Its Related Concepts :

Q.1 Consumption function is the functional relationship between _____ and_____

(a) AD and AS

(b) Consumption and AD 

(c) Consumption, National income
(d) National income and personal a income
Ans: C

Q.2 Classical theory of employment is based on the assumption of

(a) Short run

(b) Full employment
(c) Closed economy
d) Fixed price
Ans: B

Q.3 Choose the correct alternative

(a) AD curve has a positive slope

(b) AD curve originates from point of origin and has a positive slope

(c) According to Keynes, investment increases with increases in income

(d) Consumption is zero at zero level of income
Ans: A

Q.4 45° line in the context of equilibrium income is a 

(a)  Line of reference
(b) Line of identity    

(c) Line of equality between AD and AS

(d) Both (a) and (c)

Ans: D

Q.5  Aggregate Demand curve:

(a) Is a diagrammatic presentation of Aggregate Demand schedule.

(b) Shows desired expenditure corresponding to different levels of income in the economy.

(c) Indicates ex-post demand in the economy.

(d) Both (a) and (b)

Ans: D

Q.6 Consumption in Keynesian Economics depends upon 

(a) Income

(b) Saving

(c) Investment

(d) None of these

Ans: A

Q.7 Constant slope of saving curve indicates that:

(a) Saving curve will be a straight line

(b) Saving function will be non linear.

(c) Saving function will be linear.
(d) Both (a) and (c)

Ans: D

Q.8 Out of the following which value can be greater than one ?

(a) APC
(b) MPC
(c) APS

(d) MPS
Ans: A

Q.9 Break-even point is achieved when:

(a) National Income = Consumption
(b) Consumption = Saving

(c) Consumption = Investment
(d) National Income > Consumption
Ans: A

Q.10 Which of the following fact is correct about MPC ?
(a) Value of MPC varies between O and 1

(b) MPC of poor is more than that of rich

(c) MPC falls with successive increase in income

(d) All of these

Ans: D

Q.11 Break-even point occurs when:

(a) Y = S
(b) S = 0

(c) Y = C
(d) both (b) and (c)

Ans: D

Q.12 AD Curve starts :

(a) From the origin
(b) Point Below the origin
(c) Point above the origin
(d) None of these

Ans: C

Q.13 If investment falls to zero, national income does not fall to zero because of

(a) Autonomous Consumption

(b) Induced investment  

(c) Autonomous Investment

(d) Multiplier

Ans: A

Q.14 45° line in the context of equilibrium GDP is a 

(a) Line of reference
(b) Line of identity
(c) Line of equality between AS and AD
(d) Both (a) & (c)

Ans: D

Q.15 AD is:

(a) Positively related to Y
(b) Negatively related to Y 

(c) Not related to Y

(d) Always equal to Y
Ans: A

Q.16 AD curve:

(a) Is a diagrammatic presentation of AD schedule

(b) Shows desired expenditure corresponding to different levels of income in the economy

(c) Indicates ex-post demand in the economy

(d) Both (a) and (b)

Ans: D

Q.17 The slope of S-line is indicated by:

(a) MPC

(b) MPS

(c) 1 – MPC

(d) both (b) and (c)
Ans: D

Q.18 Frictional unemployment occurs due to:

(a) immobility of labour
(b) lack of production capacity

(c) low wage rate

(d) none of these
Ans: A

Q.19 Structural unemployment occurs due to:

(a) change in technology
(b) when factors (other than labour) are in shortage 

(c) both (a) and (b)
(d) none of these
Ans: C

Q.20 Natural unemployment occurs due to:

(a) shortage of factors of production

(b) time required in adjusting to change in technology 

(c) time required in shifting from one job to the other

(d) both (b) and (c)
Ans: D

Q.21 Which of the following does not lead to fall in AD ?

(a) Fall in private consumption expenditure
(b) Fall in exports

(c) Fall in import
(d) Fall in government expenditure
Ans: C

Q.22 Out of the following which value can be greater than one ? 

(a) APC
(b) MPC
(c) APS
(d) MPS
Ans: A

Q.23 At the break-even point: 

(a) Consumption curve lies above the 45o line

(b) Consumption curve lies below the 45o line

(c) Consumption curve intersects 45o line
(d) None of these
Ans: C

Q.24 Which of the following statements is not true for consumption function:

(a) Consumption expenditure is never zero even if income level is zero.

(b) Consumption expenditure increases with increase in income.

(c) Consumption expenditure can increase in a greater proportion as compared to increase in income level.
(d) None of the above
Ans: C

NCERT Most important question:

Question 1.
An index number which accounts for the relative importance of the items is known as
(i) weighted index
(ii) simple aggregative index
(iii) simple average of relatives
Answer:
(i) An index number becomes a weighted index when the relative importance of items is taken care of weighted index is the weighted average of different goods.

Question 2.
In most of the weighted index numbers the weight pertains to
(i) base year
(ii) current year
(iii) both base and current year
Answer:
(i) In general, the base period weight is preferred in calculating the weighted index number but as per Laspeyre’s method it uses the base year quantity as weight, Paache uses current year quantities as weight and Fisher’s Index Method uses both base and current year quantities.

Question 3.
The impact of change in the price of a commodity with little weight in the index will be
(i) small
(ii) large
(iii) uncertain
Answer:
(i) An equal rise in the price of an item with little weight will have lower implications for the overall change in the price ;ndex than that of an Item with more weight.

Question 4.
A consumer price index measures changes in
(i) retail prices
(ii) wholesale prices
(iii) producers’prices
Answer:
(i) Consumer Price Index (CPI), also known as the cost of living index, measures the average change in retail prices which show the most accurate impact of price rise on the cost of living of common people.

Question 5.
The item having the highest weight in consumer price index for industrial workers is
(i) food
(ii) housing
(iii) clothing
Answer:
(i) As weight and Fisher’s index method uses both base and current year quantities.
Food is given around 57% weight in CPI for industrial workers as it constitutes the major proportion of their total consumption.

Question 6.
In general, inflation is calculated by using
(i) wholesale price index
(ii) consumer price index
(iii) producer’s price index
Answer:
(i) The WPI is widely used to measure the rate of inflation. The weekly inflation rate is given by
XtXt1Xt−1×100
where X, and X_t-1 to the WPI for the (t)th and (t- 1)th weeks.

Question 7.
Why do we need an index number?
Answer:
Index number enables us to calculate a single measure of change of a large number of items. The index numbers are needed for the general and specific purpose they are

• Measurement of Change in the Price Level or the Value of ‘ Money Index number measures the value of money during different periods of time as well as we can use it to know the Impact of the change in the value of money on different sections of society. It can be worked out to correct the inflationary and deflationary gaps in the system.
• Information of Foreign Trade Index of export and import provides useful information regarding foreign trade which helps in formulating the policies of export and import.
• Calculating Real Wages CPI are used in calculating the purchasing power of money and real wage as follows
  • Purchasing power of money = 1/Cost of living index
  • Real wage = (Money wage/Cost of living index) × 100
• Measuring and Comparing Output Index of Industrial Production (IIP) gives us a quantitative figure about the change in production in the industrial sector and thus helps in comparing industrial output in different periods. Similarly, agricultural production index provides us an estimate of the production index provides us an estimate of the production in agricultural sector.
• Policy Making of Government With the help of index numbers government determines the minatory and fiscal prey and take nassery steps to develop the country.
• Indicating Stock Prices Sensex and NIFT are index numbers of share prices on BSE and NSE respectively. They serve as a useful guide for investors in the stock market. If the sensex and nifty are rising, investors have positive expectations about the future performance of the economy and it is an appropriate time for investment.

Question 8.
What are the desirable properties of the base period?
Answer:
Base period should have the following properties

• The base year should be a normal period and periods in which extraordinary events have occurred should not be taken as base periods as they are not appropriate for general comparisons.
• Extreme values should not be selected as base period.
• The period should not be too far in the past as comparison with current period cannot be done with such base year as policies, economic and social conditions change with time.
• Base period should be updated periodically.

Question 9.
Why is it essential to have different CPI for different categories of consumers?
Answer:
The Consumer Price Index (CPI) in India is calculated for different categories as under

• CPI for industrial workers.
• CPI for urban non-manual employees.
• CPI for agricultural labourers.

The reason behind calculation of three different CPIs is that the consumption pattern of the three groups (i.e., industrial workers, urban non-manual workers and agricultural labourers) differs significantly from each other. Therefore, to assess the impact of the price change on the cost of living of the three groups, component items included in the index need to be given different weights for each of the group. This necessitates the calculation of different CPI for different categories of consumers.

Question 10.
What does a consumer price index for industrial workers measure?
Answer:
Consumer price index for industrial workers measures the average change in retail prices of a basket of commodities which an industrial worker generally consumes. Consumer price index for industrial workers is increasingly being considered the appropriate indicator of general inflation, which shows the most accurate impact of price rise on the cost of living of common people.

The items included in CPI (Consumer Price Index) for industrial workers are food, pan, supari, tobacco, fuel and lighting, housing, colthing, and miscellaneous expenses with food being accorded the highest weight. This implies that the food price changes have a significant impact on the CPI.

Question 11.
What is the difference between a price index and a quantity index?
Answer:
The difference between a price index and a quantity index is as follows

• Price index numbers measure and allow for comparison of the prices of certain goods while quantity index number measure the changes in the physical volume of production, construction or employment.
• Price index numbers are more widely used as compared to quantity index numbers.
• Price index is known as unweighted index number while quantity index number is known was weighted index numbers.

Question 12.
Is the change in any price reflected in a price index number?
Answer:
No, the change in any price is not reflected in a price index number. Price index numbers measure and permit comparison of the prices of certain goods included in the basket being used to compare prices in the base period with prices in the current period. Moreover, an equal rise in the price of an item with large weight and that of an item with low weight will have different implications for the overall change in the price index.

Question 13.
Can the CPI number for urban non-manual emplyees represent the changes in the cost of living of the President of India?
Answer:
The CPI for the urban non-manual employees cannot represent the changes in the cost of living of the President of India. This is because the consumption basket of an average non-manual employee does not consist of the items that would be a part of the consumption basket of the President of India.

Question 14.
The monthly per capita expenditure incurred by workers for an industrial centre during 1980 and 2005 on the following items are given below. The weights of these items are 75, 10, 5, 6 and 4 respectively.
Prepare a weghted index number for cost of living for 2005 with 1980 as the base.

Answer:

Question 15.
Read the following table carefully and give your comments.
Answer:
Index of Industrial Production Base 1993-94

The following conclusions can be made by analysing the above table

• Manufacturing industry has the highest weight of 79.58% in Index of Industrial Production (IIP) while mining and quarrying and electricity industries account for 10.73% and 10.69% respectively.
• Manufacturing Industry has registered the highest growth among all industrial sectors in both the years 1996-97 and 2003-04.
• Mining and quarrying has registered the lowest growth rate in both the years.
• The General Index shows that industrial increased by 30.8% in 1996.-97 as compared to 1993-94 and by 89% in 2003-04.

Question 16.
Try to list the important items of consumption in your family.
Answer:
(This is a general example. You can use the actual consumption items in your family).
The following items constitute the total consumption needs for a family

• Food
• Clothing
• House-Rent/EMI of Housing loan
• Education
• Electricity
• Entertainment and recreation
• Miscellaneous expenses

Question 17.
If the salary of a person in the base year is ? 4,000 per annum and the current year salary is ? 6,000 by how much should his salary rise to maintanin the same standard of living if the CPI is 400?
Answer:
Base CPI = ₹ 100
Current CPI = ₹400
Base Year Salary = ₹ 4,000
Current Year Salary = ₹ 6,000
When Base CPI is ₹100, then the salary is = ₹ 4,000
Current salary equivalent to base year salary = (Base year salary/100) × CPI of current year
When Current CPI is ₹ 400, then the salary should be
= 4,000100×400 = ₹ 16,000 100
Thus, his salary should be X 16,000 to maintain his purchasing power. Therefore, in the current year his salary should increase by ₹ 16,000 – ₹ 6,000 = ₹ 10,000 so as to maintain the same level of living in the current year as that of the base year.

Question 18.
The consumer price index for June, 2005 was 125. The food index was 120 and that of other items
What is the percentage of the total weight given to food?
Answer:

Let the total weight = 100
W₁ denotes weight of food
W₂ denotes weight of other items
So,

Multiplying both sides of Eq. (i) by 135 and subtracting Eq. (ii) from (i) we get

So, W₁ = 100015 = 66.67
Substituting the value of in the Eq. (i), we get
W₁ + W₂ = 100
or 6667 + W₂ = 100
W₂ = 33.33
Therefore, percentage of total weight given to food is 66.67% and other items 33.33%.

Question 19.
An enquiry into the budgets of the middle class families in a certain city gave the following information

What is the cost of living index of 2004 as compared with 1995?
Answer:

Cost of Living Index = 134.50
Thus, the price rose by 34.50% during 1995 and 2004.

Question 20.
Record the daily expenditure quantities bought and prices paid per unit of the daily purchases of your family for two weeks. How has the price change affected your family?
Answer:
This is a practical exercise. Record the daily expenditure, quantities bought and prices paid per unit of the daily purchases of your family for two weeks and try to analyse if quantities purchased decrease with rise in price of the respective items and also note if the percentage change in quantity brought about by a percentage change in price differ for different types of items.

Question 21.
Given the following data

Source Economic Survey, Government of India 2004-2005
(i) Calculate the inflation rates using different index numbers.
(ii) Comment on the relative values of the index numbers.
(iii) Are they comparable?
Answer:
(i) (a) Inflation using CPI of Industrial Workers

(b) Inflation using CPI of Non-maunal Employees

(c) Inflation using CPI of Agricultural Labourers

(d) Inflation using WPI

(ii) The inflation rate calculated using CPI industrial worker with the base year 1982 is the highest and inflation rate calculated using WPI with the base year 1993-94 is the least.
(iii) No the index number are not comparable because of the following reasons

• Base periods for CPI of industrial workers, urban non-manual workers, agricultural labourers and WPI are different.
• Commodities and their weightage in different index number may be different.

NCERT Most important question:

Question 1.
The unit of correlation coefficient between height in feet and weight in kgs is
(a) kg/feet
(b) percentage
(c) non-existent
Answer:
(c) Correlation coefficient (r) has no unit. It is a pure number. It meansss units of measurement are not part of r.

Question 2.
The range of simple correlation coefficient is
(a) 0 to infinity
(b) minus one to plus one
(c) minus infinity to infinity
Answer:
(b) The value of the correlation coefficient lies between minus one and plus one, -1 ≤ r ≤ 1. If the value of r is outside this range it indicates error in calculation.

Question 3.
If r_XY is positive the relation between X and Y is of the type
(a) when Y increases X increases
(b) when Y decreases X increases
(c) when Y increases X does not change
Answer:
(a) If r is positive the two variables move in the same direction. e.g., when the price of coffee rises, the demand for tea also rises as coffee is a substitute of tea. Therefore, the r between price of coffee and demand for tea will be positive

Question 4.
If r_XY = 0, the variable X and Y are
(a) linearly related
(b) not linearly related
(c) independent
Answer:
(b) If r_XY = 0, it means the two variables are uncorrelated and there is no linear relation between them. However, other types of relation may be there and they may not be independent.

Question 5.
Of the following three measures which can measure any type of relationship?
(a) Karl Pearson’s coefficient of correlation
(b) Spearman’s rank correlation
(c) Scatter diagram
Answer:
(c) The scatter diagram gives a visual presentation of the relationship and is not confined to linear relations. Karl Pearson’s coefficient of correlation and Spearman’s rank correlation are strictly the measures of linear relationship.

Question 6.
If precisely measured data are available the simple correlation coefficient is
(a) more accurate than rank correlation coefficient
(b) less accurate than rank correlation coefficient
(c) as accurate as the rank correlation coefficient
Answer:
(a) Rank correlation should be used only when the variables cannot be measured precisely, generally it is not as accurate as the simple correlation coefficient as all the information concerning the data is not utilised in this.

Question 7.
Why is r preferred to covariance as a measure of association?
Answer:
Both, correlation coefficient and covariance measure the degree of linear relationship between two variables, but correlation coefficient is generally preferred to covariance due to the following reasons

• The correlation coefficient (r) has no unit.
• The correlation coefficient is independent of origin as well as scale.

Question 8.
Can r lie outside the -1 and 1 range depending on the type of data?
Answer:
No the value of the correlation coefficient lies between minus one and plus one, -1 ≤ r ≤ 1. If the value of r is outside this range in any type of data, it indicates error in calculation.

Question 9.
Does correlation imply causation?
Answer:
No, correlation measures do not imply causation. Correlation measures co-variation and not causation.
Correlation does not imply cause and effect relation. The knowledge of correlation only gives us an idea of the direction and intensity of change in a variable when the correlated variable changes. The presence of correlation between two variables X and Y simply means that when the value of one variable is found to change in one direction, the value of the other variable is found to change either in the same direction (i.epositive change) or in the opposite direction (i.e., negative change), in a definite way.

Question 10.
When is rank correlation more precise than simple correlation coefficient?
Answer:
Rank correlation is more precise than simple correlation coefficient in the following situations

• When the Measurements of the Variables are Suspect e.g., in a remote village where measuring rods or weighing scales are not available, height and weight of people cannot be measured precisely but the people can be easily ranked in terms of height and weight.
• When Data is Qualitative It is difficult to quantify qualities such as fairness, honesty etc. Ranking may be a better alternative to quantification of qualities.
• When Data has Extreme Values Sometimes the correlation coefficient between two variables with extreme values may be quite different from the coefficient without the extreme values. Under these circumstances rank correlation provides a better alternative to simple correlation.

Question 11.
Does zero correlation mean independence?
Answer:
No, zero correlation does not mean independence. If there is zero correlation (r_XY = 0), it means the two variables are uncorrelated and there is no linear relation between them. However, other types of relation may be there and they may not be independent.

Question 12.
Can simple correlation coefficient measure any type of relationship?
Answer:
No, simple correlation coefficient can measure only linear relationship.

Question 13.
List some variables where accurate measurement is difficult.
Answer:
Accurate measurement is difficult in case of

• Qualitative variables such as beauty, intelligence, honesty, etc.
• It is also difficult to measure subjective variables such as poverty, development, etc which are interpreted differently by different people.

Question 14.
Interpret the values of r as 1, -1 and 0.
Answer:

• If r = 0 the two variables are uncorrelated. There is no linear relation between them. However, other types of relation may be there and hence the variables may not be independent.
•  If r= 1 the correlation is perfectly positive. The relation between them is exact in the sense that if one increases, the other also increases in the same proportion and if one decreases, the other also decreases in the same proportion.
• If r = -1 the correlation is perfectly negative. The relation between them is exact in the sense that if one increases, the other decreases in the same proportion and if one decreases, the other increases in the same proportion.

Question 15.
Why does rank correlation coefficient differ from Pearsonian correlation coefficient?
Answer:
Rank correlation coefficient differs from Pearsonian correlation coefficient in the following ways

• Rank correlation coefficient is generally lower or equal to Karl Pearson’s coefficient.
• Rank correlation coefficient is preferred to measure the correlation between qualitative variables as these variables cannot be measured precisely.
• The rank correlation coefficient uses ranks instead of the full set of observations that leads to some loss of information.
• If extreme values are present in the data, then the rank correlation coefficient is more precise and reliable.

Question 16.
Calculate the correlation coefficient between the heights of fathers in inches (X) and their sons (Y).

Answer:

Note Answer: printed in NCERT is incorrect.

Question 17.
Calculate the correlation coefficient between X and Y and comment on their relationship.

Answer:

As the value of r is zero, so there is no linear correlation between X and Y.

Question 18.
Calculate the correlation coefficient between X and Y and comment on their relationship.

Solution

As the correlation coefficient between the two variables is + 1, so the two variables are perfectly positive correlated

NCERT Most important question:

Question 1

Define dispersion.

Answer: Dispersion is the measure of the extent to which different items tend to dispense away from the central tendency.

Question 2

What is the coefficient of dispersion?

Answer: The coefficient of dispersion shows different data percentage or relative value. The coefficient of dispersion is known as a relative measure of dispersion.

Question 3

Define range.

Answer: Range is the variance between the lowest and highest value in a series. Therefore, Range = Highest value in the series – Lowest value in the series.

Question 4

Explain the interquartile range.

Answer: In a series, the difference between the first Quartile (Q1) and third Quartile (Q3) is known as the interquartile range.

Question 5

What is the quartile deviation?

Answer: Half of the interquartile range is Quartile deviation. It can also be mentioned as semi-inter quartile range.

Question 6

What is the coefficient of quartile deviation formula?

Answer:  For calculating the coefficient of quartile deviation, the formula applied is.

Q3−Q1/ Q3+Q1

Question 7

Define mean deviation.

Answer: A mathematics average of the deviations of all the principles taken from some average value (mean, median, mode) of the series, ignoring signs (+ or -) of the deviation is mean deviation.

Question 8

What is standard deviation?

Answer: The square root of the arithmetic mean of the squared deviations of the items from their mean value.

Question 9

What is a Lorenz curve?

Answer: Lorenz curve is a curve that shows the actual distribution deviation (of income or wealth) from the line exhibiting equal distribution.

Question 10

Define variance.

Answer: Variance is another measure of dispersion. Variance is the square of the standard deviation.

Question 11.
A measure of dispersion is a good supplement to the central value in understanding a frequency distribution. Comment.
Answer:
Dispersion is the extent to which values in a distribution differ from the avarage of the distribution. Knowledge of only average is insufficient as it does not reflect the quantum of variation in values.

Measures of dispersion enhance the understanding of a distribution considerably by providing information about how much the actual value of items in a series deviate from the central value, e.g., per capita income gives only the average income but a measure of dispersion can tell you about income inequalities, thereby improving the understanding of the relative living standards of different sections of the society. Through value of dispersion one can better understand the distribution.

Thus a measure of dispersion is a good supplement to the central value in understanding a frequency distribution.

Question 12.
Which measure of dispersion is the best and how?
Answer:
Standard Deviation is considered to be the best measure of dispersion and is therefore the most widely used measure of dispersion.

• It is based on all values and thus provides information about the complete series. Because of this reason, a change in even one value affects the value of standard deviation.
• It is independent of origin but not of scale.
• It is us’eful in advanced statistical calculations like comparison of variability in two data sets.
• It can be used in testing of hypothesis.
• It is capable of further algebraic treatment.

Question 13.
Some measures of dispersion depend upon the spread of values whereas some calculate the variation of values from a central value. Do you agree?
Answer:
Yes, it is true that some measures of dispersion depend upon the spread of values, whereas some calculate the variation of values from the central value. Range and Quartile Deviation measure the dispersion by calculating the spread within which the value lie. Mean Deviation and Standard Deviation calculate the extent to which the values differ from the average or the central value.

Question 14.
In town, 25% of the persons earned more than ₹ 45,000 whereas 75% earned more than 18,000. Calculate the absolute and relative values of dispersion.
Answer:
25% of the persons earned more than ₹ 45,000. This implies that upper quartile Q₃ = 45,000 75% earned more than 18,000. This implies that lower quartile Q₁ =18,000
Absolute Measure of Dispersion = Q₃ – Q₁ = 45,000 – 18,000 = 27,000
Relative Measure of Dispersion
Co-efficient of Quartile Deviation

Question 15.
The yield of wheat and rice per acre for 10 districts of a state is as under

Calculate for each crop,
(i) Range
(ii) QD
(iii) Mean’Deviation about Mean
(iv) Mean Deviation about Median
(v) Standard Deviation
(vi) Which crop has greater variation?
(vii) Compare the value of different measures for each crop.
Answer:
(i) Range
(a) Wheat Highest value of distribution (H) = 25
Lowest value of distribution (L) = 9
Range = H – L = 25 – 9 = 16
(b) Rice Highest value of distribution (H) = 34
Lowest value of distribution (L)=12
Range = H – L = 34 – 12 = 22
(ii) Quartile Deviation
(a) Wheat Arranging the production of wheat in increasing order 9, 10, 10, 12, 15, 16, 18, 19, 21, 25
Q₁ = N+14th item = 10+14th item = 114th item
= 2.75th item
= Size of 2nd item + 0.75 (size of 3rd item – size of 2nd item)
= 10 + 0.75(10 – 10)
= 10 + 0.75 × 0
= 10
Q₃ = 3(N+1)4th item = 3(10+1)4th item
= 334th item = 8.25th
= Size of 8th item + 0.25 (size of 9th item – size of 8th item)
= 19 + 0.25(21 – 19)
= 19 + 0.25 × 2
= 19 + 0.50 = 19.50
Quartile Deviation = Q3−Q12=19.50−102=9.502 = 4.75
(b) Rice Arranging the data of production of rice
12, 12, 12, 15, 18, 18, 22, 23, 29, 34 item
Q₁ = N+14th item = 10+14th item
= 2.75 th item
= Size of 2nd item + 0.75 (size of 3rd item – size of 2nd item)
= 12 + 0.75(12 – 12) = 12 + 0.75 × 0
= 12

= 8.25th item
= Size of 8th item + 0.25 (size of 9th item – size of 8th item)
= 23 + 0.25(29 – 23)
= 23 + 0.25 × 6
= 23 + 1.5
= 24.5
Quartile Deviation = Q3−Q12=24.5−122=12.502 = 6.25

(iii) Mean Deviation about Mean
(a) Wheat

(b) Rice

(iv) Mean Deviation about Median
(a) Wheat

(b) Rice

(v) Standard Deviation
(a) Wheat

(b) Rice

(vi) Coefficient of Variation
(a) Wheat
CV =σX¯¯¯¯¯×100=5.0415.5×100 = 32.51
(b) Rice
CV =σX×100=7.1619.5×100 = 36.71
Rice crop has greater variation as the coefficient of variation is higher for rice as compared to that of wheat.
(vii) Rice crop has higher Range, Quartile Deviation, Mean Deviation about Mean, Mean Deviation about Median, Standard Deviation and Coefficient of Variation.

Question 16.
A batsman is to be selected for a cricket team. The choice is between X and Y on the basis of their scores in five previous scores which are

Which batsman should be selected if we want,
(i) a higher run-getter, or
(ii) a more reliable batsman in the team?
Answer:
Batsman X

(i) Average of Batsman X is higher than that of Batsman Y, so he should be selected if we want a high scorer.
(ii) The Batsman Y is more reliable than Batsman X. This is because the coefficient of variation of Batsman X is higher than that of Batsman Y.

Question 17.
To check the quality of two brands of light bulbs, their life in burning hours was estimated as under for 100 bulbs of each brand.

(i) Which brand gives higher life?
(ii) Which brand is more dependable?
Answer:
For Brand A

For Brand B