Radiations of two photons having energies twi | vedclass

Name: Exam Paper Generator | JEE NEET Paper Generator | Vedclass
Brand: Vedclass
Rating: 5 (35 reviews)

Question

(B) According to Einstein's photoelectric equation,the maximum kinetic energy $(K.E._{\max})$ is given by $K.E._{\max} = E - \phi_0$,where $E$ is the

Vedclass · Accepted Answer

$1: 2$

Vedclass · Answer

(B) According to Einstein's photoelectric equation,the maximum kinetic energy $(K.E._{\max})$ is given by $K.E._{\max} = E - \phi_0$,where $E$ is the energy of the incident photon and $\phi_0$ is the work function of the metal.For the first case,$E_1 = 2\phi_0$,so $K.E._{\max 1} = 2\phi_0 - \phi_0 = \phi_0$.For the second case,$E_2 = 5\phi_0$,so $K.E._{\max 2} = 5\phi_0 - \phi_0 = 4\phi_0$.The ratio of maximum kinetic energies is $\frac{K.E._{\max 1}}{K.E._{\max 2}} = \frac{\phi_0}{4\phi_0} = \frac{1}{4}$.Since $K.E._{\max} = \frac{1}{2}mv_{\max}^2$,the ratio of velocities is $\frac{v_1}{v_2} = \sqrt{\frac{K.E._{\max 1}}{K.E._{\max 2}}} = \sqrt{\frac{1}{4}} = \frac{1}{2}$.

Radiations of two photons having energies twice and five times the work function of a metal are incident successively on a metal surface. The ratio of the maximum velocity of photoelectrons emitted in the two cases will be

Similar Questions

When a metal is irradiated by light having wavelength $\lambda$ $(\lambda < \lambda_0)$,all the photoelectrons emitted are bent in a circle of radius $r$ by a magnetic field of flux density $B_0$. Find $\frac{1}{\lambda_0}$,where $\lambda_0$ is the threshold wavelength.

The photoelectric threshold wavelength for potassium (work function being $2 \ eV$) is ........... $nm$.

Two photons of energies twice and thrice the work function of a metal are incident on the metal surface. Then,the ratio of maximum velocities of the photoelectrons emitted in the two cases respectively,is

$A$ beam of light falls on a metal surface such that photo-electrons are generated. If the power of the light source starts to decrease linearly with time $t$, then the variation of the photocurrent $I$ and the magnitude of the stopping potential $|V|$ with time is best represented by:

Vedclass Test Series

Exam Paper Generator

Online Exam Module