The ratio of longest wavelength and the shortest wavelength observed in the five spectral series of emission spectrum of hydrogen is 
(1) $\frac{4}{3}$             

(2) $\frac{525}{376}$

(3) 25

(4) $\frac{900}{11}$

In Bohr's model of hydrogen atom, let PE represents potential energy and TE the total energy. In going to a higher level 

(1) PE decreases, TE increases

(2) PE increases, TE increases

(3) PE decreases, TE decreases

(4) PE increases, TE decreases

 According to Bohr's model, the radius of the second orbit of helium atom is 
(1) 0.53 Å             

(2) 1.06 Å

(3) 2.12 Å             

(4) 0.265 Å

The fact that photons carry energy was established by

(1) Doppler's effect               

(2) Compton's effect

(3) Bohr's theory                   

(4) Diffraction of light

An ionic atom equivalent to hydrogen atom has wavelength equal to 1/4 of the wavelengths of hydrogen lines. The ion will be 
(1) ${\mathrm{He}}^{+}$        

(2) ${\mathrm{Li}}^{++}$

(3) ${\mathrm{Ne}}^{9+}$       

(4) ${\mathrm{Na}}^{10+}$

The third line of Balmer series of an ion equivalent to hydrogen atom has wavelength of 108.5 nm. The ground state energy of an electron of this ion will be 
(1) 3.4 eV               

(2) 13.6 eV

(3) 54.4 eV             

(4) 122.4 eV

Hydrogen atom emits blue light when it changes from n = 4 energy level to the n = 2 level. Which colour of light would the atom emit when it changes from the n = 5 level to the n = 2 level 
(1) Red                   

(2) Yellow

(3) Green               

(4) Violet

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

The wavelength of the energy emitted when electrons come from the fourth orbit to the second orbit in hydrogen is \(20.397~\text{cm}\). The wavelength of energy for the same transition in \(\mathrm{He^{+}}\) is:
1. \(5.099~\text{cm}\)
2. \(20.497~\text{cm}\)
3. \(40.994~\text{cm}\)
4. \(81.988~\text{cm}\)

Minimum excitation potential of Bohr's first orbit in hydrogen atom is
(1) 13.6 V                     

(2) 3.4 V

(3) 10.2 V                     

(4) 3.6 V