Assertion : The de-Broglie wavelength of a molecule varies inversely as the square root of temperature.
Reason : The root mean square velocity of the molecule depends on the temperature.

1. If both the assertion and the reason are true and the reason is a correct explanation of the assertion
2. If both the assertion and reason are true but the reason is not a correct explanation of the assertion
3. If the assertion is true but the reason is false
4. If both the assertion and reason are false

In X-ray tube, the accelerating potential applied at the anode is V volt. The minimum wavelength of the emitted X-ray will be :

(1) eV/h

(2) h/eV

(3) eV/ch

(4) hc/eV

A parallel beam of light is incident normally on a plane surface absorbing 40% of the light and reflecting the rest. If the incident beam carries 60 W of power, the force exerted by it on the surface is

(1) $3.2\times {10}^{-8} N$

(2) $3.2\times {10}^{-7} N$

(3) $5.12\times {10}^{-7} N$

(4) $5.12\times {10}^{-8} N$

In the following diagram if ${\mathrm{V}}_2>{\mathrm{V}}_1$, then,

(1) ${\mathrm{\lambda }}_1=\sqrt{{\mathrm{\lambda }}_2}$

(2) ${\mathrm{\lambda }}_1<{\mathrm{\lambda }}_2$

(3) ${\mathrm{\lambda }}_1={\mathrm{\lambda }}_2$

(4) ${\mathrm{\lambda }}_1>{\mathrm{\lambda }}_2$

The value of stopping potential in the following diagram

(1) – 4V
(2) – 3 V
(3) – 2V
(4) – 1 V

The correct curve between the stopping potential (V) and intensity of incident light (I) is

For a photoelectric cell the graph showing the variation of cut of voltage (${\mathrm{V}}_0$) with frequency (v) of incident light is best represented by

The graph between intensity of light falling on a metallic plate (I) with the current (i) generated is

The stopping potential as a function of the frequency of the incident radiation is plotted for two different photoelectric surfaces A and B. The graphs show that work function of A is 

(1) Greater than that of B
(2) Smaller than that of B
(3) Equal to that of B
(4) No inference can be drawn about their work functions from the given graphs