# Nuclei Class 12 Physics Chapter 13 MCQ Question Answer NCERT Solution

Class 12 Physics Chapter 13 objective type / mcq question answer of Nuclei NCERT Solution in Hindi. NCERT Class 12 Physics MCQ Question Answer and Important Question Answer, Textual Question answer also Available for Various Board Students like HBSE, CBSE, UP board, Mp Board, RBSE and some other State Boards.

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NCERT Solution for Class 12 Physics Chapter 13 Nuclei MCQ Question Answer.

## Nuclei Class 12 MCQ Question Answer

1. Who discovered neutron ?
(A) Bohr
(C) J J Thomson
(D) None of the above

2. 1 Decay per second are equivalent to what unit of radioactivity ?
(A) Kelvin
(B) Curie
(C) becquerel
(D) Newton

Ans. (C) becquerel

3. When two nuclei (A ≤ 10) fuse together to form a heavier nucleus, the
(A) binding energy per nucleon increases.
(B) binding energy per nucleon decreases.
(C) binding energy per nucleon does not change.
(D) total binding energy decreases.

Ans. (A) binding energy per nucleon increases.

4. In Β decay, a
(A) neutron converts into a proton emitting antineutrino.
(B) neutron converts into a proton emitting neutrino.
(C) proton converts into a neutron emitting antineutrino.
(D) proton converts into a neutron emitting neutrino

Ans. (A) neutron converts into a proton emitting antineutrino.

5. Number and type of nucleons in the nucleus of Deuterium  (1H2) will be :
(A) 2 protons
(B) 1 proton and 1 neutron
(C) 2 neutrons
(D) 1 proton and 1 electron

Ans. (B) 1 proton and 1 neutron

6. Two nuclei have mass numbers in the ratio 1 : 8. What is the ratio of nuclear density ?
(A) 1 : 4
(B) 1 : 2
(C) 1 : 1
(D) 1 : 8

Ans. (C) 1 : 1

7. The energy equivalent of 1 amu is
(A) 900 MeV
(B) 921 MeV
(C) 931 MeV
(D) None of the above

Ans. (C) 931 MeV

8. Electron emission from a metallic surface is possible only, when Frequency of the incident Light is :
(A) Less Then threshold Frequency
(B) Half of the Threshold Frequency
(C) Greater than the Threshold Frequency
(D) No effect of Frequency