Class 12 Physics MCQ Chapter 12 Atoms

Class 12 Physics MCQ Chapter 12 Atoms Solutions English Medium to each chapter is provided in the list so that you can easily browse through different chapters Class 12 Physics MCQ Chapter 12 Atoms Question Answer in English and select need one. AHSEC Class 12 Physics Objective Type Question Answer As Per AHSEC New Book Syllabus Download PDF. AHSEC Physics MCQ Class 12 Solutions.

Class 12 Physics MCQ Chapter 12 Atoms

Also, you can read the NCERT book online in these sections Solutions by Expert Teachers as per Central Board of Secondary Education (CBSE) Book guidelines. AHSEC Class 12 Physics Multiple Choice Solutions in English Medium are part of All Subject Solutions. Here we have given AHSEC Class 12 Physics MCQ Question Answer English Medium for All Chapters, You can practice these here.

Atoms

Chapter: 12

MCQs

1. The model of the atom proposed by Rutherford is –

(i) Plum pudding model.

(ii) Nuclear model.

(iii) Planetary model.

(iv) Quantum model.

Ans: (iii) Planetary model.

2. According to Bohr’s model, the angular momentum of an electron is quantized in units of –

(i) hhh

(ii) h/2π

(iii) h/4π

(iv) h/π

Ans: (ii) h/2π

3. Which physical quantity remains conserved in Bohr’s atomic model?

(i) Linear momentum.

(ii) Angular momentum.

(iii) Energy only.

(iv) Charge.

Ans: (ii) Angular momentum.

4. Bohr’s theory is applicable to –

(i) One electron systems only.

(ii) All atoms.

(iii) Molecules.

(iv) Multielectron systems.

Ans: (i) One electron systems only.

5. The energy of an electron in the nth orbit is –

(i) Positive.

(ii) Zero.

(iii) Negative.

(iv) Infinite.

Ans: (iii ) Negative.

6. The energy of electron in ground state of hydrogen is –

(i) –13.6 eV

(ii) –3.4 eV

(iii) 0

(iv) +13.6 eV

Ans: (i)  –13.6 eV.

7. The radius of first Bohr orbit is –

(i) 1.06 × 10⁻¹⁰ m.

(ii) 5.29 × 10⁻¹¹ m.

(iii) 1.6 × 10⁻¹⁹ m.

(iv) 3.14 × 10⁻¹⁰ m.

Ans: (ii) 5.29 × 10⁻¹¹ m.

8. Bohr radius is proportional to –

(i) n

(ii) n²

(iii) 1/n

(iv) 1/n²

Ans: (ii) n²

9. The speed of electron in first orbit of hydrogen is –

(i) 2.18 × 10⁶ m/s

(ii) 3 × 10⁸ m/s

(iii) 1.6 × 10⁻¹⁹ m/s

(iv) 9.1 × 10⁻³¹ m/s

Ans: (i) 2.18 × 10⁶ m/s.

10. Which of the following series lies in visible region?

(i) Lyman.

(ii) Balmer.

(iii) Paschen.

(iv) Brackett.

Ans: (ii) Balmer.

11. Energy of nth orbit of hydrogen atom is –

(i) Directly proportional to n.

(ii) Inversely proportional to n².

(iii) Inversely proportional to n.

(iv) Independent of n.

Ans: (ii) Inversely proportional to n².

12. First line of Lyman series is due to –

(i) n=2 → n=1

(ii) n=3 → n=1

(iii) n=2 → n=2

(iv) n=4 → n=3

Ans: (i) n=2 → n=1.

13. In hydrogen atom, when electron jumps from n=3 to n=2, it emits –

(i) Hα

(ii) Hβ

(iii) Lyman line

(iv) Paschen line

Ans: (i) Hα.

14. Total energy of hydrogen atom in nth orbit is –

(i) 13.6/n²

(ii) –13.6/n

(iii) –13.6/n²

(iv) –n²/13.6

Ans: (iii)  –13.6/n².

15. Kinetic energy of electron in Bohr’s orbit is –

(i) Equal to total energy.

(ii) Negative.

(iii) Positive.

(iv) Equal to potential energy.

Ans: (iii) Positive.