NCERT Class 12 Chapter 13 Physics Nuclei MCQ

NCERT Class 12 Chapter 13 Physics Nuclei MCQ | Questions & Answers: Here is an article that could help you in learning new things about the Nuclei concept in NCERT Class 12 Physics Chapter 13. Students of Class 12 can make perfect use of this opportunity to attempt the online quiz to test their depth of knowledge.

1. The constituents of nucleus are

A. electrons and protons

B. protons and neutrons

C. neutrons and electrons

D. electrons, protons and neutrons

2. When a β-particle is emitted from a nucleus then its neutron-proton ratio

A. increases

B. decreases

C. remains unchanged

D. may increase or decrease depending upon the nucleus.

3. In nuclear reactors, the control rods are made of

A. cadmium

B. graphite

C. krypton

D. plutonium

4. The nuclide

has all the following except

A. 92 protons

B. 146 neutrons

C. 238 nucleons

D. 92 electrons

5. The radius of a nucleus is

A. directly proportional to its mass number

B. inversely proportional to its atomic weight

C. directly proportional to the cube root of its mass number

D. None of these

6. The relation between half-life T_1/2 of a radioactive sample and its mean life x is

CBSE Class12 Physics Nuclei (6Q)

A. (a)

B. (b)

C. (c)

D. (d)

7. When the mass of a sample of a radioactive substance decreases, the mean life of the sample:

A. increases

B. decreases

C. remain unchanged

D. first decreases then increases

8. Which one of the following statements about the atomic nucleus is accurate?

A. The nucleus is held together mostly by the electrical and gravitational forces

B. Large nuclei are denser than light nuclei

C. All nuclei have nearly the same density

D. Smaller nuclei are denser than larger nuclei

9. A nuclei having same number of neutron but different number of protons / atomic number are called

A. isobars

B. isomers

C. isotones

D. isotopes

10. The quantity which is not conserved in a nuclear reaction is

A. momentum.

B. charge

C. mass

D. none of these.

11. A nuclear explosive is designed to deliver 1 MW power in the form of heat energy. If the explosion is designed with nuclear fuel consisting of U235 to run a reactor at this power level for one year, then the amount of fuel needed is (given energy per fission is 200 MeV)

A. 1 kg

B. 0.01 kg

C. 3.84 kg

D. 0.384 kg

12. Nucleus ''a'' contains 5 protons and 5 neutrons and has radius R. The radius of nucleus ''b'', which contains 35 protons and 45 neutrons, is closest to:

A. 2R

B. 8R

C. 1.4R

D. R

13. When the number of nucleons in nuclei increases, the binding energy per nucleon

A. increases continuously with mass number

B. decreases continuously with mass number

C. remains constant with mass number

D. first increases and then decreases with increase of mass number

14. The half-life of a radioactive nucleus is 3 hours. In 9 hours, its activity will be reduced to a factor of CBSE Class12 Physics Nuclei (14Q)

A. (a)

B. (b)

C. (c)

D. (d)

15. Particles which can be added to the nucleus of an atom without changing its chemical properties are called

A. neutrons

B. electrons

C. protons

D. alpha particles

16. Binding energy per nucleon is the ratio of

A. the binding energy of the nucleus to the number of nucleons in that nucleus.

B. energy required to remove a nucleon to atomic weight

C. binding energy of a nucleon to the atomic number

D. binding energy of a nucleus to the atomic number

17. The mass of an atomic nucleus is less than the sum of the masses of its constituents. This mass defect is converted into

A. heat energy

B. light energy

C. electrical energy

D. energy which binds nucleons together

18. A radioactive element has half-life period 1600 years. After 6400 years what amount will remain? CBSE Class12 Physics Nuclei (18Q)

A. (a)

B. (b)

C. (c)

D. (d)

19. The neutron was discovered by whom?

A. Marie Curie

B. Pierre Curie

C. Rutherford

D. James Chadwick

20. The atomic number Z of the nucleus is

A. Number of deutrons

B. Number of neutrons in it

C. Number if electrons in it.

D. Number of protons in it.

21. Nuclear forces are

A. spin dependent and have no non-central part

B. spin dependent and have a non-central part

C. pin independent and have no non-central part

D. spin independent and have a non-central part

22. Ratio of the radii of the nuclei with mass numbers 8 and 27 would be CBSE Class12 Physics Nuclei (22Q)

A. (a)

B. (b)

C. (c)

D. (d)

23. The mass of an atomic nucleus is less than the sum of the masses of its constituents. This mass defect is converted into

A. heat energy

B. light energy

C. electrical energy

D. energy which binds nucleons together

24. The density of nuclear matter is:

A. independent of the number of nucleons in the nucleus

B. directly proportional to the number of neutrons in the nucleus

C. directly proportional to the number of protons in the nucleus

D. directly proportional to the square of the number of nucleons in the nucleus

25. On an average, the number of neutrons and the energy of a neutron released per fission of a uranium atom are respectively

A. 2.5 and 2 keV

B. 3 and l keV

C. 2.5 and 2 MeV

D. 2 and 2 keV