CBSE Class 11 Physics Physical World And Measurement Worksheet

Physical World Important Points Class 11 Physics

• Science is a systematic way of acquiring knowledge about the surroundings through careful observations and experimentations over a period of time.
• The study of nature and natural phenomenon put in an organized way in various subtopics is called physics. It has many branches namely, mechanics, electricity, magnetism, optics, modern physics, etc.
• Physics covers a tremendous range of magnitude of physical quantities such as length, mass, time, energy, etc.
• The connection between physics and technology can be observed in many examples.
• Carnot’s theory of heat engine enabled man to develop refrigerators, engine, air conditioner, etc.
• Study of electromagnetic waves and propagation helped man to design communication systems.
• The idea of the nucleus and the energy embedded in it enabled him to generate an enormous amount of energy.
• Physics and technology are related to each other.
• Physics in relation to society:
• Physics has tried to help humankind to develop better ideas. Development of the transport system and communication system has brought the world closer.

Fundamental forces in nature:

• Gravitational force: The gravitational force exists between any two objects in the universe. It states that the force of mutual attraction is directly proportional to the product of the masses and inversely proportional to the square of the separation.
• Electro-magnetic force: The electromagnetic force is between a pair of charges/poles. The electric and magnetic forces are not separable.
• Strong-nuclear force: The strong nuclear forces bind the protons and neutrons in a nucleus.
• Weak-nuclear forces: The weak nuclear forces appear in certain interactions such as β- decay and exist in distances of the order of 10–15 m.

The electromagnetic and the weak nuclear forces are unified into one force called electro-weak force.

Conserved Quantities

• The quantities that remain constant with time for a system.

Conservation law:
Some of the general laws in nature include the laws of conservation of mass, energy, linear momentum, angular momentum, charge, parity, etc. Some conservation laws are true for
one fundamental force but not for the other.

Law of Conservation of Energy: For motion under an external conservative force, the total mechanical energy (that is the sum of kinetic and potential energy of a body) remains
constant.

Law of Conservation of Linear Momentum: In the absence of an external force, the linear momentum of a system remains unchanged.

Law of Conservation of Angular Momentum: If the total external torque acting on a system is zero, then angular momentum of the system remains constant.

Law of Conservation of Charge: Charges are neither created nor destroyed, but are simply transferred from one body to another.

Question. Which of the following is wrongly matched ?
(a) Barometer-Pressure
(b) Lactometer-Milk
(c) Coulomb’s law-charges
(d) Humidity-Calorimeter

Answer: D

Question. Who discovered X-rays?
(a) Chadwick
(b) Roentgen
(c) Thomson
(d) Madam Curie

Answer: B

Question. The scientific principle involves in production of ultra high magnetic fields is
(a) super conductivity
(b) digital logic
(c) photoelectric effect
(d) laws of thermodynamics

Answer: A

Question. Louis de-Broglie is credited for his work on
(a) theory of relativity
(b) electromagnetic theory
(c) matter waves
(d) law of distribution of velocities

Answer: C

Question. The man who has won Nobel Prize twice in physics is
(a) Einstein
(b) Bardeen
(c) Heisenberg
(d) Faraday

Answer: B

Question. The branch of science which deals with nature and natural phenomena is called
(a) Sociology
(b) Biology
(c) Civics
(d) Physics

Answer: D

Question. Which of the following is the correct decreasing order of the strengths of four fundamental forces of nature ?
(a) Electromagnetic force > weak nuclear force > gravitational force > strong nuclear force
(b) Strong nuclear force > weak nuclear force > electromagnetic force > gravitational force
(c) Gravitational force > electromagnetic force > strong nuclear force > weak nuclear force
(d) Strong nuclear force > electromagnetic force > weak nuclear force > gravitational force

Answer: D

Question. In Rutherford, alpha particle scattering experiment as shown in given figure, A and B refer to (23)
(a) polonium sample and aluminium foil
(b) polonium sample and gold foil
(c) uranium sample and gold foil
(d) uranium sample and aluminium foil

Answer: B

Question. Madam Marie Curie won Nobel Prize twice which were in the field of
(a) Physics and chemistry
(b) Chemistry only
(c) Physics only
(d) Biology only

Answer: A

Question. The person who has been awarded the title of the Father of Physics of 20th century is
(a) Madame Curie
(b) Sir C.V. Raman
(c) Neils Bohar
(d) Albert Einstein

Answer: D

Question. Who gave general theory of relativity?
(a) Einstein
(b) Marconi
(c) Ampere
(d) Newton

Answer: A

Question. Which of the following has infinite range?
(a) Gravitational force
(b) Electromagnetic force
(c) Strong nuclear force
(d) Both (a) and (b)

Answer: D

Question. Which of the following is true regarding the physical science?
(a) They deal with non-living things
(b) The study of matter are conducted at atomic or ionic levels
(c) Both (a) and (b)
(d) None of these

Answer: C

Question. C.V. Raman got Nobel Prize for his experiment on
(a) dispersion of light
(b) reflection of light
(c) deflection of light
(d) scattering of light

Answer: D

Question. The field of work of S. Chandrashekar is
(a) theory of black hole
(b) Cosmic rays
(c) theory of relativity
(d) X-rays

Answer: A

Question. Prof. Albert Einstein got nobel prize in physics for his work on
(a) special theory of relativity
(b) general theory of relativity
(c) photoelectric effect
(d) theory of specific heats

Answer: C

Question. Two Indian born physicists who have been awarded Nobel Prize in Physics are
(a) H. J. Bhabha and APJ Kalam
(b) C.V. Raman and S. Chandrasekhar
(c) J.C. Bose and M.N. Saha
(d) S. N. Bose and H. J. Bhabha

Answer: B

Question. The exchange particles for the electromagnetic force are
(a) gravitons
(b) gluons
(c) photons
(d) mesons

Answer: C

Question. Science is exploring, ...x... and ...y... from what we see around us. Here, x and y refer to
(a) qualitative, modify
(b) experiment, predict
(c) verification, predict
(d) reasoning, quantitative

Answer: B

Question. The man who is known as the Father of Experimental Physics is
(a) Newton
(b) Albert Einstein
(c) Galileo
(d) Rutherford

Answer: C

Question. A scientific way of doing things involve
(a) identifying the problem
(b) collecting data
(c) hypothesising a possible theory
(d) All of the above

Answer: D

Question. Which of the following is the weakest force?
(a) Nuclear force
(b) Gravitational force
(c) Electromagnetic force
(d) None of these

Answer: B

Question. Macroscopic domain includes
(a) phenomena at the laboratory
(b) terrestrial scales
(c) astronomical scales
(d) All of the above

Answer: D

Each question contains
STATEMENT-1 and STATEMENT-2. Choose the correct answer
(a) Statement -1 is false, Statement-2 is true
(b) Statement -1 is true, Statement-2 is true; Statement -2 is a correct explanation for Statement-1
(c) Statement -1 is true, Statement-2 is true; Statement -2 is not a correct explanation for Statement-1
(d) Statement -1 is true, Statement-2 is false 

Question. Statement-1 : Electromagnetic force is much stronger than the gravitational farce.
Statement-2 : Electromagnetic force dominates all phenomena at atomic and molecular scales.

Answer: B

Question. Statement-1 : The concept of energy is central to Physics and expression for energy can be written for every physical system.
Statement-2 : Law of conservation of energy is not valid for all forces and for any kind of transformation between different forms of energy.

Answer: D

Question- A scientific way of doing things involve

(a) identifying the problem

(b) collecting data

(c) hypothesising a possible theory

(d) All of the above

Answer-(d)

Question- The person who has been awarded the title of the Father of Physics of 20th century is

(a) Madame Curie

(b) Sir C.V. Raman

(c) Neils Bohar

(d) Albert Einstein

Answer-(d)

Question- Who discovered X-rays?

(a) Chadwick

(b) Roentgen

(c) Thomson

(d) Madam Curie

Answer-(b)

Question- Two Indian born physicists who have been awarded Nobel Prize in Physics are

(a) H. J. Bhabha and APJ Kalam

(b) C.V. Raman and S. Chandrasekhar

(c) J.C. Bose and M.N. Saha

(d) S. N. Bose and H. J. Bhabha

Answer-(b)

Question- Macroscopic domain includes

(a) phenomena at the laboratory

(b) terrestrial scales

(c) astronomical scales

(d) All of the above

Answer-(d)

Question- Prof. Albert Einstein got nobel prize in physics for his work on

(a) special theory of relativity

(b) general theory of relativity

(c) photoelectric effect

(d) theory of specific heats

Answer-(c)

Question- When we hold a book in our hand, we are balancing the gravitational force on the book due to

(a) normal force provided by our hand

(b) friction force provided by our book

(c) both (a) and (b)

(d) None of these

Answer-(a)

Question- Which of the following is wrongly matched ?

(a) Barometer-Pressure

(b) Lactometer-Milk

(c) Coulomb’s law-charges

(d) Humidity-Calorimeter

Answer-(d)

Question- The man who is known as the Father of Experimental Physics is

(a) Newton

(b) Albert Einstein

(c) Galileo

(d) Rutherford

Answer-(c)

Question- C.V. Raman got Nobel Prize for his experiment on

(a) dispersion of light

(b) reflection of light

(c) deflection of light

(d) scattering of light

Answer-(d)

Question- The branch of science which deals with nature and natural phenomena is called

(a) Sociology

(b) Biology

(c) Civics

(d) Physics

Answer-(d)

Question- Louis de-Broglie is credited for his work on

(a) theory of relativity

(b) electromagnetic theory

(c) matter waves

(d) law of distribution of velocities

Answer-(c)

Question- The man who has won Nobel Prize twice in physics is

(a) Einstein

(b) Bardeen

(c) Heisenberg

(d) Faraday

Answer-(b)

Question- Madam Marie Curie won Nobel Prize twice which were in the field of

(a) Physics and chemistry

(b) Chemistry only

(c) Physics only

(d) Biology only

Answer-(a)

Question- The scientific principle involves in production of ultra high magnetic fields is

(a) super conductivity

(b) digital logic

(c) photoelectric effect

(d) laws of thermodynamics

Answer-(a)

Question- Which of the following has infinite range?

(a) Gravitational force

(b) Electromagnetic force

(c) Strong nuclear force

(d) Both (a) and (b)

Answer-(d)

Question- Which of the following is true regarding the physical science?

(a) They deal with non-living things

(b) The study of matter are conducted at atomic or ionic levels

(c) Both (a) and (b)

(d) None of these

Answer-(c)

Question-  Which of the following is the weakest force?

(a) Nuclear force

(b) Gravitational force

(c) Electromagnetic force

(d) None of these

Answer-(b)

Question- Which of the following is the correct decreasing order of the strengths of four fundamental forces of nature ?

(a) Electromagnetic force > weak nuclear force > gravitational force > strong nuclear force

(b) Strong nuclear force > weak nuclear force > electromagnetic force > gravitational force

(c) Gravitational force > electromagnetic force > strong nuclear force > weak nuclear force

(d) Strong nuclear force > electromagnetic force > weak nuclear force > gravitational force

Answer-(d)

Question- The exchange particles for the electromagnetic force are

(a) gravitons

(b) gluons

(c) photons

(d) mesons

Answer-(c)

Question- Who gave general theory of relativity?