Number of ejected photoelectron increases with increase
in intensity of light
in wavelength of light
in frequency of light
Never
In a discharge tube ionisation of enclosed gas is produced due to collisions between
positive ions and neutral atoms/molecules
negative electrons and neutral atoms / molecules
photons and neutral atoms / molecules
neutral gas atoms / molecules
A light source is at a distance d from a photoelectric cell, then the number of photoelectrons emitted from the cell is n. If the distance of light source and cell is reduced to half, then the number of photoelectrons emitted will become
2n
4 n
n
Which of the following is true ?
The stopping potential increases with increasing intensity of incident light
The photocurrent increases with increasing intensity of light
The current in photocell increases with increasing frequency of light
The photocurrent is proportional to applied voltage
Monochromatic light of frequency 6.0×1014 Hz is produced by a laser. The power emitted is 2× 10-3 W. The number of photons emitted, on the average, by the source per second is
5 × 1015
5 × 1016
5 × 1017
5 × 1014
The energy of a photon of light is 3 eV. Then the wavelength of photon must be
4125 nm
412.5 nm
41250 nm
4 nm
Monochromatic light of wavelength 667 nm is produced by a helium neon laser. The power emitted is 9 mW. The number of photons arriving per second on the average at a target irradiated by this beam is
9 × 1017
3 × 1016
9 × 1015
3 × 1019
Ultraviolet radiation of 6.2eV falls on an aluminium surface. KE of fastest electron emitted is (work function = 4.2 eV)
3.2 × 10-21 J
3.2 × 10-19 J
7 × 10-25 J
9 × 10-32 J
According to Einstein's photoelectric equation, the graph between the kinetic energy of photoeletrons ejected and the frequency of incident radiation is
The work function of a surface of a photosensitive material is 6.2 eV. The wavelength of the incident radiation for which the stopping potential is 5 V lies in the
ultraviolet region
visible region
infrared region
X-ray region
