When the light source is kept 20 cm away from a photo cell, stopping potential 0.6 V is obtained. When source is kept 40 cm away, the stopping potential will be 
1. 0.3 V                  2. 0.6 V
3. 1.2 V                  4. 2.4 V

If in a photoelectric experiment, the wavelength of incident radiation is reduced from 6000 Å to 4000 Å then

(1) Stopping potential will decrease
(2) Stopping potential will increase
(3) Kinetic energy of emitted electrons will decrease
(4) The value of work function will decrease

Which of the following is dependent on the intensity of incident radiation in a photoelectric experiment

(1) Work function of the surface

(2) Amount of photoelectric current

(3) Stopping potential will be reduced

(4) Maximum kinetic energy of photoelectrons

Which of the following statements is correct

(1) The current in a photocell increases with increasing frequency of light

(2) The photocurrent is proportional to applied voltage

(3) The photocurrent increases with increasing intensity of light

(4) The stopping potential increases with increasing intensity of incident light

4 eV is the energy of the incident photon and the work function in 2eV. What is the stopping potential ?

(1) 2V                   

(2) 4V

(3) 6V                   

(4) $2\sqrt{2} \mathrm{V}$ 

The magnitude of saturation photoelectric current depends upon 

(1) Frequency             

(2) Intensity

(3) Work function       

(4) Stopping potential

A particle of mass M at rest decays into two particles of masses ${\mathrm{m}}_1$ and ${\mathrm{m}}_2$, having non-zero velocities. The ratio of the de-Broglie wavelengths of the particles, $\raisebox{1ex}{${\mathrm{\lambda }}_1$}\!\left/ \!\raisebox{-1ex}{${\mathrm{\lambda }}_2$}\right.$is

(a) ${\mathrm{m}}_1$/${\mathrm{m}}_2$              (b) ${\mathrm{m}}_2$/${\mathrm{m}}_1$
(c) 1.0                   (d) $\sqrt{{\mathrm{m}}_2}/\sqrt{{\mathrm{m}}_1}$

A photon and an electron have equal energy E, then ${\mathrm{\lambda }}_{\mathrm{photon}}/{\mathrm{\lambda }}_{\mathrm{electron}}$ is proportional to

(1) $\sqrt{\mathrm{E}}$                     

(2) $1/\sqrt{\mathrm{E}}$
(3) 1/E                       

(4) Does not depend upon E

A photon of $1.7\times {10}^{-13}$ Joules is absorbed by a material under special circumstances. The correct statement is:

1. Electrons of the atom of absorbed material will go the higher energy states

2. Electron and positron pair will be created

3. Only positron will be produced

4. Photoelectric effect will occur and electron will be produced

In a photoemissive cell with executing wavelength $\mathrm{\lambda }$, the fastest electron has speed v. If the exciting wavelength is changed to 3$\mathrm{\lambda }$/4, the speed of the fastest emitted electron will be 
(a) $\mathrm{v}{\left(3/4\right)}^{1/2}$                              (b) $\mathrm{v}{\left(4/3\right)}^{1/2}$
(c) Less than $\mathrm{v}{\left(4/3\right)}^{1/2}$               (d) Greater than $\mathrm{v}{\left(4/3\right)}^{1/2}$