In Lenard's experiment, ultraviolet light of wavelength 200 nm is incident on a metal surface. The stopping potential is found to be 4V. If the wavelength is increased to 300 nm, what will be the new stopping potential? (Take $h = 6.63 imes 10^{-34}$ Js, $c = 3 imes 10^8$ m/s, $e = 1.6 imes 10^{-19}$ C)

The number of photons per second on an average emitted by the source of monochromatic light of wavelength 600 nm, when it delivers the power of $3.3 imes {10^{ - 3}}$ watt will be $(h = 6.6 imes {10^{ - 34}}{\rm{Js)}}$

If ${n_R}$ and ${n_V}$ denote the number of photons emitted by a red bulb and violet bulb of equal power in a given time, then

When ultraviolet rays are incident on metal plate, then photoelectric effect does not occur. It occurs by the incidence of

Monochromatic light of wavelength $3000\mathop A\limits^ \circ$ is incident on a surface area 4 ${\rm{c}}{{\rm{m}}^2}$. If intensity of light is 150mW${{\rm{m}}^{ - 2}}$, then rate at which photones strike the target is

Light of frequency $1.8

u_0$(where$

u_0$is the threshold frequency) is incident on a metal surface. If the intensity is quadrupled and the frequency is changed to$0.9

u_0$, what will be the observed photocurrent?

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

In a photoelectric effect experiment, the slope of the graph between the stopping potential and the incident frequency will be

For a body moving with relativistic speed, if the velocity is doubled, then

A metal surface with work function $\phi$ is illuminated by monochromatic light of frequency $

u$. If the stopping potential is$V_0$, and the mass of an electron is$m$, the maximum speed of the emitted photoelectrons is:

Ultraviolet radiation of 6.2eV falls on an aluminium surface (work function 4.2eV). The kinetic energy in joule of the fastest electron emitted is approximately