JOIN ADRE 2.0 Telegram Group

NCERT Solutions for class 12 Physics | Chapter 12 - Atoms

Questions
1 The Bohr model of atoms
A assumes that the angular momentum of elec-trons is quantized.
B uses Einstein’s photoelectric equation.
C predicts continuous emission spectra for at-oms.
D predicts the same emission spectra for all types of atoms.

Answer:assumes that the angular momentum of elec-trons is quantized.
2 The first spectral series was discovered by
A Balmer
B Lyman
C Paschen
D Pfund

Answer:Balmer
Advertisement
Article and Schedule Quiz Start Test!

DOWNLOAD CURRENT AFFAIRS PDF FROM APP

3 In the Geiger-Marsden scattering experiment the number of scattered particles detected are maximum and minimum at the scattering angles respectively at
A 0° and 180°
B 180° and 0°
C 90° and 180°
D 45° and 90°

Answer:0° and 180°
4 Which of the following spectral series falls within the visible range of electromagnetic radiation?
A Lyman series
B Balmer series
C Paschen seriee
D Pfund series

Answer:Balmer series
5 In Geiger-Marsden scattering experiment, the trajectory traced by an a-particle depends on
A number of collision
B number of scattered a-particles
C impact parameter
D none of these

Answer:impact parameter
6 Which of the following postulates of the Bohr model led to the quantization of energy of the hydrogen atom?
A The electron goes around the nucleus in circular orbits.
B The angular momentum of the electron can only be an integral multiple of h/2π.
C The magnitude of the linear momentum of the electron is quantized.
D Quantization of energy is itself a postulate of the Bohr model.

Answer:The angular momentum of the electron can only be an integral multiple of h/2π.
7 If the radius of inner most electronic orbit of a hydrogen atom is 5.3 * 10~n m, then the radii of n = 2 orbits is
A 1.12 Å
B 2.12 Å
C 3.22 Å
D 4.54 Å

Answer:2.12 Å
8 In the Geiger-Marsden scattering experiment, is case of head-on collision the impact parameter should be
A maximum
B minimum
C infinite
D zero

Answer:maximum
9 The first model of atom in 1898 was proposed by
A Ernst Rutherford
B Albert Einstein
C J.J. Thomson
D Niels Bohr

Answer:J.J. Thomson
10 The diagram shows the energy levels for an electron in a certain atom. Which transition shown represents the emission of a photon with the most energy?

Class 12 Physics Chapter 12 Atoms

A I
B II
C III
D IV

Answer:III
11 The total energy that will be released if a nucleus is built from its constituents is called the:
A binding energy of the nucleus
B binding energy of the solid
C binding energy of the atom
D None of these

Answer:binding energy of the nucleus
12 Natural radioactivity was discovered by:
A Joliot
B Becquerel
C Pauli
D None of these

Answer:Becquerel
13 The energy equivalent to mass defect is called :
A binding energy
B internal energy
C external energy
D enthalpy

Answer:binding energy
14 P-decay produces:
A isobars
B isotopes
C isotones
D All the above

Answer:isobars
15 Transmutation of nuclei was discovered by:
A Rutherford
B Becquerel
C Pauli
D None of these

Answer:Rutherford
16 For ionization of excited Hydrogen atom, the, required energy is:
A a little less than 13.6
B equal to 13.6
C more than 13.6
D 3.4 or less

Answer:3.4 or less
17 The concept of electron spin was introduced by:
A Becquerel
B Goudsmit
C Millikan
D Uhlenbeek and Goudsmit

Answer:Uhlenbeek and Goudsmit
18 The mass of a neutron is:
A 1.00866 u
B 1.0866 u
C 1.866 u
D 0.1866 u

Answer:1.00866 u
19 The energy equivalent to one atomic mass unit is :
A 1.6 × 10-19 J
B 6.02 × 1023 J
C 9.31 MeV
D 931 MeV

Answer:931 MeV
20 Half-life of a substance depends on:
A pressure
B temperature
C density
D None of these

Answer:None of these

ADRE 2.0 FULL LENGTH MOCK TEST

Take Mock Tests

Missiles Mock Test Start Test!
SSC MTS Mock Test Start Test
IBPS CLERK MOCK TEST Start Test
SSC MTS 2022 JULY 26 Shift 1 (ENGLISH) Start Test!
SSC GD Previous Year Paper 2021 Nov 17 Shift - I (Hindi) Start Test!
SSC CGL Tier - 1 PYP 2022 April 21 Shift- 1 (ENGLISH) Start Test!
MPSC PAPER I MOCK TEST 1 (ENGLISH) Start Test!
IB Security Assistant Mock test 1 (english) Start Test!
UP POLICE CONSTABLE MOCK TEST 1 Start Test!
DELHI POLICE CONSTABLE MOCK TEST 1 (HINDI) Start Test!

Chapters

Advertisement
Assam Direct Recruitment Test Series