NCERT Class 12 MCQ Quiz Hub

1. An atom stays in an excited state for about:
10 micro seconds
10 milli seconds
10 nano seconds
10 seconds

2. The energy equivalent to one atomic mass unit is :
1.6 × 10-19 J
6.02 × 1023 J
9.31 MeV
931 MeV

3. Who explained the splitting of special lines in magnetic field?
Zeeman
Bohr
Summerfield
Einstein

4. The mass of a neutron is:
1.00866 u
1.0866 u
1.866 u
0.1866 u

5. Isobars have the same:
A
Z
N
All the above

6. Isotones have the same:
A
Z
Neutron
All the above

7. Half-life of a substance depends on:
pressure
temperature
density
None of the these

8. The concept of electron spin was introduced by:
Becquerel
Goudsmit
Millikan
Uhlenbeek and Goudsmit

9. The principle that a quantum orbital cannot be occupied by more than two electrons was given by:
Pauli
Millikan
Hund
None of the above

10. For ionization of excited Hydrogen atom, the, required energy is:
a little less than 13.6
equal to 13.6
more than 13.6
3.4 or less

11. Artificial radioactivity was discovered by:
Joliot
Becquerel
Pauli
None of the above

12. P-decay produces:
isobars
isotopes
isotones
All the above

13. Natural radioactivity was discovered by:
Joliot
Becquerel
Pauli
None of the above

14. Transmutation of nuclei was discovered by:
Rutherford
Becquerel
Pauli
None of the above

15. The energy equivalent to mass defect is called :
binding energy
internal energy
external energy
enthalpy

16. The total energy that will be released if a nucleus is built from its constituents is called the:
binding energy of the nucleus
binding energy of the solid
binding energy of the atom
None of the above

17. The binding energy of 42He is about:
28.3 eV
28.3 MeV
28.3 J
2.83 MeV

18. The binding energy of a deuteron is about:
2.22 MeV
2.22 J
2.22 eV
None of the these