# Atoms Class 12 Physics Chapter 12 MCQ Question Answer NCERT Solution

Class 12 Physics Chapter 12 objective type / mcq question answer of Atoms 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 12 Atoms MCQ Question Answer.

## Atoms Class 12 MCQ Question Answer

1. Which model of atom suggests that atom is a spherical cloud of positive charges with electrons embedded in it ?
(A) Rutherford model
(B) Bohr model
(C) Thomson model
(D) de Broglie

Ans. (C) Thomson model

2. Who discovered the nucleus ?
(A) Thomson
(B) Bohr
(C) Rutherford
(D) de Broglie

Ans. (C) Rutherford

3. In the α-particle scattering experiment, the shape of the trajectory of the scattered α-particles depend upon :
(a) only on impact parameter.
(b) only on the source of α-particles
(c) both impact parameter and source of α-particles
(d) impact parameter and the screen material of the detector.

Ans. (a) only on impact parameter.

4. Whose model of atom is also called nuclear model of atom ?
(A) Thomson
(B) Rutherford
(C) de Broglie
(D) Bohr

Ans. (B) Rutherford

5. According to Rutherford’s experiments, the size of nucleus is about :
(A) 10-11 m to 10-10 m
(B) 10-13 m to 10-12 m
(C) 10-15 m to 10-14 m
(D) 10-12 m to 10-11 m

Ans. (C) 10-15 m to 10-14 m

6. Which of the following statements is not correct according to Rutherford model ?
(A) Most of the space inside an atom is empty.
(B) The electrons revolve around the nucleus under the influence of coulomb force acting on them.
(C) Most part of the mass of the atom and its positive charge are concentrated at its centre.
(D) The stability of atom was established by the model

Ans. (D) The stability of atom was established by the model

7. In Bohr’s model of hydrogen atom, the total energy of the electron in nth discrete orbit is proportional to
(A) n
(B) 1/n
(C) n2
(D) 1/n2

Ans. (D) 1/n2

8. Paschen series of atomic spectrum of hydrogen gas lies in :
(a) Infrared region
(b) Ultraviolet region
(c) Visible region
(d) Partly in ultraviolet and partly in visible region

Ans. (a) Infrared region

9. Which spectral series of hydrogen atom lies in the ultraviolet region ?
(A) Lyman
(B) Balmer
(C) Paschen
(D) Brackett

Ans. (A) Lyman

10. The ionization energy of hydrogen atom is :
(A) 13.6 J
(B) 13.6 eV
(C) 1 eV
(D) 10.2 eV

Ans. (B) 13.6 eV

11. The energy of an atom in ground state is –3.4 eV. The ionisation energy of this atom is :
(A) 1.7 eV
(B) 6.8 eV
(C) 3.4 eV
(D) 5.1 eV

Ans. (C) 3.4 eV

12. The energy of an atom in ground state is –4.9 eV. The ionisation energy of this atom is :
(A) 2.45 eV
(B) 13.6 eV
(C) 9.8 eV
(D) 4.9 eV