# Atomic Physics Theory MCQ Question with Answer

## Atomic Physics Theory MCQ with detailed explanation for interview, entrance and competitive exams. Explanation are given for understanding. Question No : 1
The mass of an electron in motion depends upon:

direction of motion
its velocity
its velocity of e-
it's shell number

Question No : 2
The mass and energy equivalent to 1 a.m.u. respectively are :

1.67 x 10-27 g, 9.30 MeV
1.67 x 10-27 kg, 930 MeV
1.67 x 10-27 kg, 1 MeV
1.67 x 10-34 kg, 1 MeV

Question No : 3
It is given for the azimuthal quantum number l = 3, the total number of different possible values of the magnetic azimuthal quantum number, ml is :

3
7
4
5

Question No : 4
The acceleration of electron in the first orbit of hydrogen atom is:

$\frac{4{\mathrm{\pi }}^{2}\mathrm{m}}{{h}^{3}}$
$\frac{{h}^{2}}{4{\mathrm{\pi }}^{2}\mathrm{mr}}$
$\frac{{h}^{2}}{4{\mathrm{\pi }}^{2}{\mathrm{m}}^{2}{\mathrm{r}}^{3}}$
$\frac{{m}^{2}{h}^{2}}{4{\mathrm{\pi }}^{2}{\mathrm{r}}^{3}}$

Question No : 5
If the electron in a hydrogen atom jumps from an orbit level n1 = 3 to an orbit level n2 = 2, the emitted radiation has a wavelength given by :

$\lambda =\frac{36}{5R}$
$\lambda =\frac{5R}{36}$
$\lambda =\frac{6}{R}$
$\lambda =\frac{R}{6}$

Question No : 6
Number of electrons that constitute one ampere of current is :

265x1016
625x1012
4.8 x 1010
625x1016

Question No : 7
The angular momentum of electron in hydrogen atom is proportional to :

$\sqrt{r}$
$\frac{1}{r}$
${r}^{2}$
$\frac{1}{\sqrt{r}}$