In photoelectric effect, the kinetic energy of photoelectrons increases linearly with the:
1. Wavelength of incident light.
2. Frequency of incident light.
3. Velocity of incident light.
4. Atomic mass of an element.
Electrons are emitted with zero velocity from a metal surface when it is exposed to radiation of wavelength 6800 Å. The work function (W0) of the metal is:
1. 3.109 × 10–20 J
2. 2.922 × 10–19 J
3. 4.031 × 1019 J
4. 2.319 × 10–18 J
The photoelectric emission from a surface starts only when the light incident upon the surface has a certain minimum:
1. | Intensity | 2. | Wavelength |
3. | Frequency | 4. | Velocity |
A photon of wavelength 4 × 10–7 m strikes a metal surface, the work function of the metal being 2.13 eV. The kinetic energy of emission would be:
1. | 0.97 eV | 2. | 97 eV |
3. | 4.97 × eV | 4. | 5.84 × 105 eV |
The work function of the Cesium atom is \(1.9~\mathrm{eV}.\) What is the threshold frequency of radiation for this atom?
1. | \(4.59 \times10^{14}~s^{-1}\) | 2. | \(8.59 \times10^{14}~s^{-1}\) |
3. | \(5.59 \times10^{-14}~s^{-1}\) | 4. | \(65.9 \times10^{14}~s^{-1}\) |
1. 32.22 × 10–16 J
2. 12.22 × 10–16 J
3. 22.27 × 10–16 J
4. 31.22 × 10–16 J
A photon with an initial frequency of \(10^{11}~\mathrm{Hz}\) scatters off an electron at rest. Its final frequency is \(0.9 \times10^{11}~\mathrm{Hz}.\) The speed of scattered electron is close to:
1. | \(3 \times10^{2}~\mathrm{ms}^{-1}\) | 2. | \(3.8 \times10^{3}~\mathrm{ms}^{-1}\) |
3. | \(2 \times10^{6}~\mathrm{ms}^{-1}\) | 4. | \(30~\mathrm{ms}^{-1}\) |
The ejection of the photoelectron from the silver metal can be stopped by applying a voltage of 0.35 eV when the radiation having a wavelength of 256.7 nm is used. The work function for silver metal is:
1. 3.40 eV
2. 5.18 eV
3. 4.48 eV
4. –4.40 eV
The ratio of slopes of curves in photoelectric effect gives -
(v=frequency, =maximum kinetic energy, stopping potential):
1. Charge of electron
2. Planck's constant
3. Work function
4. The ratio of Planck's constant of electronic charge