If V be the accelerating voltage, then the maximum frequency of continuous x-rays is given by

1.  $\frac{eh}{V}$

2.  $\frac{hV}{e}$

3.  $\frac{eV}{h}$

4. $\frac{h}{eV}$

When a metallic surface is illuminated with radiation of wavelength $\lambda$, the stopping potential is V. If the same surface is illuminated with radiation of wavelength 2$\lambda$, the stopping potential is $\frac{V}{4}$ .The threshold wavelength for metallic surface is:

1. 5$\lambda$               
2. $\frac{5}{2}$$\lambda$
3. 3$\lambda$               
4. 4$\lambda$

Photoelectric emission occurs only when the incident light has more than a certain minimum 

1. wavelength

2. intensity

3. frequency

4. power

The threshold frequency for a photo-sensitive metal is $3.3\times {10}^{14} \mathrm{Hz}.$ If the light of frequency $8.2\times {10}^{14} \mathrm{Hz}$ is incident on this metal, the cut-off voltage for the photo-electric emission is nearly:

1. 2 V                                        2. 3 V

3. 5 V                                         4. 1 V

The figure shows a plot of photo current versus anode potential for a photo sensitive surface for three difference radiations. Which one of the following is a correct statement?

1. Curves a and b represent incident radiations of different frequencies and different intensities

2. Curves a and b represent incident radiations of same frequency but of different intensities 

3. Curves b and c represent incident radiations of different frequencies and different intensities

4. Curves b and c represent incident radiations of same frequency having same intensity 

Cathode rays are similar to visible light rays in that

(1) They both can be deflected by electric and magnetic fields

(2) They both have a definite magnitude of wavelength

(3) They both can ionize a gas through which they pass

(4) They both can expose a photographic plate

Dual nature of radiation is shown by:

(1) Diffraction and reflection

(2) Refraction and diffraction

(3) Photoelectric effect alone

(4) Photoelectric effect and diffraction

Kinetic energy with which the electrons are emitted from the metal surface due to photoelectric effect is 

(1) Independent of the intensity of illumination

(2) Independent of the frequency of light

(3) Inversely proportional to the intensity of illumination

(4) Directly proportional to the intensity of illumination

The electrons are emitted in the photoelectric effect from a metal surface 

(1) Only if the frequency of the incident radiation is above a certain threshold value

(2) Only if the temperature of the surface is high

(3) At a rate that is independent of the nature of the metal

(4) With a maximum velocity proportional to the frequency of the incident radiation