12. ATOMS( Objective Question Answer 2022 )

1. Who explained the splitting of special lines in magnetic field ?

(A) Zeeman
(B) Bohr
(C) Summerfield
(D) Einstein

2. The mass of a neutron is :

(A) 1.00866 u
(B) 1.0866 u
(C) 1.866 u
(D) 0.1866 u

3. Isobars have the same :

(A) A
(B) Z
(C) N
(D) All the above

4. Isotones have the same :

(A) A
(B) Z
(C) N
(D) All the above

5. Half-life of a substance depends on :

(A) pressure
(B) temperature
(C) density
(D) None of these

6. The concept of electron spin was introduced by :

(A) Becquerel
(B) Goudsmit
(C) Millikan
(D) Uhlenbeek and Goudsmit

7. The principle that a quantum orbital cannot be occupied by more than two electrons was given by :

(A) Pauli
(B) Millikan
(C) Hund
(D) None of these

8. The binding energy of ⁴/₂He is about :

(A) 28.3 eV
(B) 28.3 MeV
(C) 28.3 J
(D) 2.83 MeV

9. The binding energy of a deuteron is about :

(A) 2.22 MeV
(B) 2.22 J
(C) 2.22 eV
(D) None of these

10. If the atom ²⁵⁷/₁₀₀ Fm follows. Bohr model and the radius of this atom is n times Bohr radius, then n will be :

(A) 100
(B) 200
(D) 100
(C) 1/100

11. The volume occupied by an atom is greater than the volume of the nucleus by a factor of about :

(A) 10⁵
(B) 10¹⁰
(C) 10¹⁵
(D) 10

12. For Hydrogen atom, the ratio of energy in its first to second excited state is :

(A) 1/4
(B) 2/3
(C) 4/9
(D) 4/1

13. The shortest wavelength of X-rays emitted from an X-ray tube depend on the :

(A) current in the tube
(B) Voltage applied to the tube
(C) Nature fo the gas in the tube
(D) atomic number of target material

14. The speed of an electron in the orbit of hydrogen atom in ground state is :

(A) C
(B) C/2
(C) C/10
(D) C/137

15. The unit is defined as 1/12 of the mass of a carbon-12 atom and is symbolised as u. lu ^{u is equal to :}

(A) 1.66 x 10^-27 kg
(B) 1.66 x 10^-24 kg
(C) 166 x 10^-22 kg
(D) None of these

16. Who discovered the positron ?

(A) Chadwick
(B) Bohr
(C) Maxwell
(D) Anderson

17. The mass of proton is about :

(A) 9.11 x 10^-31 kg
(B) 9.11 x 10^-30 kg
(C) 1.66 x 10^-27 kg
(D) 1 kg

Class 12th physics objective question in English