If R is the Rydberg’s constant for hydrogen the wave number of the first line in the Lyman series will be

(1) $\frac{\mathrm{R}}{4}$                   

(2) $\frac{3\mathrm{R}}{4}$
(3) $\frac{\mathrm{R}}{2}$                 

(4) 2R

In hydrogen atom, if the difference in the energy of the electron in n =2 and n = 3 orbits is E, the ionization energy of hydrogen atom is 

(1) 13.2 E               

(2) 7.2 E

(3) 5.6 E                 

(4) 3.2 E

The first member of the Paschen series in hydrogen spectrum is of wavelength 18,800 Å. The short wavelengths limit of Paschen series is 

(1) 1215 Å     

(2) 6560 Å

(3) 8225 Å     

(4) 12850 Å

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 electron in a hydrogen atom makes a transition from an excited state to the ground state. Which of the following statements is true 

The ratio of minimum to maximum wavelength in Balmer series is 

(1) 5 : 9           

(2) 5 : 36

(3) 1 : 4           

(4) 3 : 4

Rutherford’s $\mathrm{\alpha }$-particle experiment showed that the atoms have

(1) Proton         

(2) Nucleus

(3) Neutron     

(4) Electrons

Which of the following is true for number of spectral lines in going from Lyman series to Pfund series ?

(1) Increases

(2) Decreases

(3) Unchanged

(4) May decreases or increases