If an electron in a hydrogen atom jumps from the 3rd orbit to the 2nd orbit, it emits a photon of wavelength$\lambda$. When it jumps from the 4th orbit to the 3rd orbit, the corresponding wavelength of the photon will be 

(1) $\frac{9}{16}\lambda$

(2) $\frac{20}{7}\lambda$

(3) $\frac{20}{13}\lambda$

(4) $\frac{16}{25}\lambda$

The ratio of kinetic energy to the total energy of an electron in a a Bohr orbit of the hydrogen atom, is

(1) 2: - 1

(2) 1: - 1

(3) 1:1

(4) 1: - 2

In the spectrum of hydrogen, the ratio of the longest wavelength in the Lyman series to the longest wavelength in the Balmer series is

(1) $\frac{5}{27}$

(2) $\frac{4}{9}$

(3) $\frac{9}{4}$

(4) $\frac{27}{5}$

Hydrogen atom in ground state is excited by a monochromatic radiation of $\lambda =975<mspace\; width="1em"></mspace>\stackrel{0}{A}$. Number of spectral lines in the resulting spectrum emitted will be 

(1) 3

(2) 2

(3) 6

(4) 10

Ratio of longest wavelengths corresponding to Lyman and Balmer series in hydrogen spectrum is

(1) $\frac{5}{27}$

(2) $\frac{3}{23}$

(3) $\frac{7}{29}$

(4) $\frac{9}{31}$

The transition from the state n = 3 to n = 1 in hydrogen like atom results in ultraviolet radiation. Infrared radiation will be obtained in the transition from

(1) 4$\to$2

(2) 4$\to$3

(3) 2$\to$1

(4) 3$\to$2

Monochromatic radiation emitted when electron in hydrogen atom jump from first excited to the ground state irradiates a photosensitive material. The stopping potential is measured to be 3.57 V. The threshold frequency of the material is

(1) $4\times {10}^{15}<mspace\; width="1em"></mspace>Hz$

(2) $5\times {10}^{15}<mspace\; width="1em"></mspace>Hz$

(3) $1.6\times {10}^{15}<mspace\; width="1em"></mspace>Hz$

(4) $2.5\times {10}^{15}<mspace\; width="1em"></mspace>\mathrm{Hz}$

Electron in hydrogen atom first jumps from third excited state to second excited state and then from second excited to the first excited state. The ratio of the wavelength ${\lambda }_1:{\lambda }_2$ emitted in the two cases is

(1) 7/5

(2) 27/20

(3) 27/5

(4) 20/7

Out of the following which one is not possible energy for a photon to be emitted by a hydrogen atom according to the Bohr's atomic model?

(1) 0.65 eV

(2) 1.9 eV

(3) 11.1 eV

(4) 13.6 eV

The electron in the hydrogen atom jumps from the excited state (n = 3) to its ground state ( n = 1) and the photons thus emitted irradiate a photosensitive material. If the work function of the material is 5.1 eV, the stopping potential is estimated to be (the energy of the electron in nth state $E_n=-\frac{13.6}{n^2}eV$)

(1) 12.1 V

(2) 17.2 V

(3) 7 V

(4) 5.1 V