Advertisements
Advertisements
प्रश्न
Calculate the maximum kinetic energy and maximum velocity of the photoelectrons emitted when the stopping potential is 81 V for the photoelectric emission experiment.
Advertisements
उत्तर
V0 = 81 V
e = 1.6 × 10−19 C
m = 9.1 × 10−31 kg
Maximum kinetic energy of electron,
Kmax = `"eV"_0`
= 1.6 × 10−19 × 81
= 129.6 × 10−19
= 1.29 × 10−17
Kmax = 1.3 × 10−17 J
Maximum velocity of photoelectron,
vmax = `sqrt((2"eV"_0)/"m")`
= `sqrt((2 xx 1.6 xx 10^-19 xx 81)/(9.1 xx 10^-31))`
= `sqrt((259.2 xx 10^-19)/(9.1 xx 10^-31))`
= `sqrt(28.48 xx 10^12)`
vmax = 5.3 × 106 ms−1
APPEARS IN
संबंधित प्रश्न
In photoelectric emission, a radiation whose frequency is 4 times threshold frequency of a certain metal is incident on the metal. Then the maximum possible velocity of the emitted electron will be
The threshold wavelength for a metal surface whose photoelectric work function is 3.313 eV is __________.
Photons of wavelength λ are incident on a metal. The most energetic electrons ejected from the metal are bent into a circular arc of radius R by a perpendicular magnetic field having magnitude B. The work function of the metal is
Define stopping potential.
List out the laws of photoelectric effect.
Explain experimentally observed facts of the photoelectric effect with the help of Einstein’s explanation.
When a light of frequency 9 × 1014 Hz is incident on a metal surface, photoelectrons are emitted with a maximum speed of 8 × 105 ms−1. Determine the threshold frequency of the surface.
A 3310 Å photon liberates an electron from a material with energy 3 × 10−19 J while another 5000 Å photon ejects an electron with energy 0.972 × 10−19 J from the same material. Determine the value of Planck’s constant and the threshold wavelength of the material.
At the given point of time, the earth receives energy from the sun at 4 cal cm–2 min–1. Determine the number of photons received on the surface of the Earth per cm2 per minute. (Given: Mean wavelength of sunlight = 5500 Å)
UV light of wavelength 1800 Å is incident on a lithium surface whose threshold wavelength is 4965 Å. Determine the maximum energy of the electron emitted.
