NCERT MOST IMPORTANT QUESTIONS CLASS – 11 | PHYSICS IMPORTANT QUESTIONS | CHAPTER – 1 | PHYSICAL WORLD | EDUGROWN |

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.