The energy of a photon of light of wavelength 450 nm is

(1) $4.4\times {10}^{-19} \mathrm{J}$             

(2) $2.5\times {10}^{-19} \mathrm{J}$

(3) $1.25\times {10}^{-17} \mathrm{J}$            

(4) $2.5\times {10}^{-17} \mathrm{J}$

Which of the following is true for photon 
(1) $\mathrm{E}=\frac{\mathrm{hc}}{\mathrm{\lambda }}$         

(2) $\mathrm{E}=\frac{1}{2}{\mathrm{mu}}^2$

(3) $\mathrm{p}=\frac{\mathrm{E}}{2\mathrm{v}}$         

(4) $\mathrm{E}=\frac{1}{2}{\mathrm{mc}}^2$

Which of the following is incorrect statement regarding photon: 

(1) Photon exerts no pressure

(2) Photon energy is hv

(3) Photon rest mass is zero

(4) None of these

There are ${\mathrm{n}}_1$ photons of frequency ${\mathrm{\gamma }}_1$ in a beam of light. In an equally energetic beam, there are ${\mathrm{n}}_2$ photons of frequency ${\mathrm{\gamma }}_2$ . Then the correct relation is -
1. $\frac{{\mathrm{n}}_1}{{\mathrm{n}}_2}=1$                       

2.  $\frac{{\mathrm{n}}_1}{{\mathrm{n}}_2}=\frac{{\mathrm{\gamma }}_1}{{\mathrm{\gamma }}_2}$
3.  $\frac{{\mathrm{n}}_1}{{\mathrm{n}}_2}=\frac{{\mathrm{\gamma }}_2}{{\mathrm{\gamma }}_1}$                     

4.  $\frac{{\mathrm{n}}_1}{{\mathrm{n}}_2}=\frac{{\mathrm{\gamma }}_1^2}{{\mathrm{\gamma }}_2^2}$

Einstein's photoelectric equation states that \(E_k=h \nu -\phi.\)${\mathrm{}}_{}$ In this equation \(E_k\) refers to:

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 threshold wavelength for photoelectric emission from a material is 5200 Å. Photo-electrons will be emitted when this material is illuminated with monochromatic radiation from :

(1) 50-watt infrared lamp

(2) 50-watt ultraviolet lamp

(3) 1-watt ultraviolet lamp

(4) Both (2) and (3)

The threshold frequency of a metal is \(10^{15}~\text{Hz}.\) When light with a wavelength \(\lambda=4000~\mathring{\text{A}}\) is incident on its surface, which of the following statements is accurate?

Einstein got Nobel prize on which of the following works

(1) Mass-energy relation

(2) Special theory of relativity

(3) Photoelectric equation

(4) (a) and (b) both

The photo-electrons emitted from a surface of sodium metal are such that 

(1) They all are of the same frequency

(2) They have the same kinetic energy

(3) They have the same de Broglie wavelength

(4) They have their speeds varying from zero to a certain maximum