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
The threshold wavelength for a metal surface whose photoelectric work function is 3.313 eV is __________.
A light of wavelength 500 nm is incident on a sensitive metal plate of photoelectric work function 1.235 eV. The kinetic energy of the photoelectrons emitted is (Take h = 6.6 × 10–34 Js)
The work functions for metals A, B and C are 1.92 eV, 2.0 eV and 5.0 eV respectively. The metal/metals which will emit photoelectrons for a radiation of wavelength 4100Å is/are
Mention the different types of photocells.
Explain how frequency of incident light varies with stopping potential.
Explain the quantum concept of light.
Explain experimentally observed facts of the photoelectric effect with the help of Einstein’s explanation.
Calculate the energies of the photons associated with the following radiation:
- violet light of 413 nm
- X-rays of 0.1 nm
- radio waves of 10 m
When a 6000 Å light falls on the cathode of a photo cell, photoemission takes place. If a potential of 0.8 V is required to stop emission of electron, then determine the
- frequency of the light
- energy of the incident photon
- work function of the cathode material
- threshold frequency and
- net energy of the electron after it leaves 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.
