brodidit for students
Nuclear physics
Class 12 · Physics · 9 questions
Name: ____________________ Date: ____________
Binding energy of a nucleus is the energy needed to:
- A Heat it
- B Rotate it
- C Add an electron
- D Separate it into nucleons
The mass defect is the difference between the:
- A Mass of two atoms
- B Mass of separate nucleons and the nucleus
- C Charge and mass
- D Atomic and mass number
A radioactive sample has a half life of 5 hours. After 15 hours the fraction left is:
- A 1/2
- B 1/4
- C 1/8
- D 1/3
Beta decay increases the atomic number by:
- A 0
- B 1
- C 4
- D 2
A fission chain reaction is controlled in a reactor using:
- A Water only
- B More uranium
- C Air
- D Control rods
The energy released from 1 atomic mass unit converted completely is about:
- A 9310 MeV
- B 931 MeV
- C 9.31 MeV
- D 93 MeV
The strong nuclear force acts between:
- A Molecules
- B Electrons only
- C Atoms only
- D Nucleons
A nuclear reactor uses a moderator to:
- A Slow down neutrons
- B Absorb all neutrons
- C Cool the fuel only
- D Speed up neutrons
The unit of radioactivity is the:
- A Gray only
- B Joule
- C Tesla
- D Becquerel
Answer key
1. D, 2. B, 3. C, 4. B, 5. D, 6. B, 7. D, 8. A, 9. D
It is the energy that holds the nucleons together.
The nucleus is lighter than the sum of its nucleons.
Three half lives: (1/2)³ = 1/8.
In beta minus decay a neutron changes into a proton.
Control rods absorb neutrons.
1 u corresponds to about 931 MeV.
It holds protons and neutrons together.
Slow neutrons cause fission more easily.
One becquerel is one decay per second.