When a hydrogen atom is excited from ground state to first excited state then the incorrect option is– 

1. its kinetic energy increases by $10.2<mspace\; width="1em"></mspace>\mathrm{eV}$ 

2. its kinetic energy decreases by $10.2<mspace\; width="1em"></mspace>\mathrm{eV}$ 

3. its potential energy increases by $20.4<mspace\; width="1em"></mspace>\mathrm{eV}$ 

4. its angular momentum increases by $1.05<mspace\; width="1em"></mspace>\times <mspace\; width="1em"></mspace>{10}^{–34}<mspace\; width="1em"></mspace>\mathrm{J}$-s

The ratio of the speed of the electrons in the ground state of hydrogen to the speed of light in vacuum is

1. 1/2                2. 2/137
3. 1/137            4. 1/237

The energy of the highest energy photon of Balmer series of hydrogen spectrum is close to
(1) 13.6 eV             

(2) 3.4 eV

(3) 1.5 eV               

(4) 0.85 eV

Taking Rydberg’s constant ${\mathrm{R}}_{\mathrm{H}}=1.097\times {10}^7<mspace\; width="1em"></mspace>\mathrm{m}$ first and second wavelength of Balmer series in hydrogen spectrum is

(1) 2000 Å, 3000 Å                 

(2) 1575 Å, 2960 Å

(3) 6529 Å, 4280 Å                 

(4) 6552 Å, 4863 Å

The de-Broglie wavelength of an electron in the first Bohr orbit is 

(1) Equal to one fourth the circumference of the first orbit

(2) Equal to half the circumference of the first orbit

(3) Equal to twice the circumference of the first orbit

(4) Equal to the circumference of the first orbit

The first line in the Lyman series has wavelength $\mathrm{\lambda }$. The wavelength of the first line in Balmer series is

(1) $\frac{2}{9}\mathrm{\lambda }$             

(2) $\frac{9}{2}\mathrm{\lambda }$
(3) $\frac{5}{27}\mathrm{\lambda }$           

(4) $\frac{27}{5}\mathrm{\lambda }$

In Bohr model of hydrogen atom, the ratio of periods of revolution of an electron in n =2 and n = 1 orbits is

(1) 2 : 1             

(2) 4 : 1

(3) 8 : 1             

(4) 16 : 1

The hydrogen gas with its atoms in the ground state is excited by monochromatic radiation of \(\lambda = 975~\mathring{{A}}.\) The number of spectral lines in the resulting spectrum emitted will be:
1. \(3\)
2. \(2\)
3. \(6\)
4. \(10\)

 For electron moving in ${\mathrm{n}}^{\mathrm{th}}$ orbit of H-atom the angular velocity is proportional to 
(1) n                       

(2) 1/n

(3) ${\mathrm{n}}^3$                    

(4) 1/${\mathrm{n}}^3$

The first line of Balmer series has wavelength 6563 Å. What will be the wavelength of the first member of Lyman series

(1) 1215.4 Å             

(2) 2500 Å

(3) 7500 Å               

(4) 600 Å