Photons of frequency f is incident on a metal surface of threshold frequency f0 . The maximum K.E. of emitted photoelectrons is
  • h(f + f0)
  • hf0
  • h(f - f0)
  • hf
The photoelectric threshold frequency of a metal is fWhen light of frequency 4f0 is incident on the metal, the maximum K.E. of the emitted electron is
  • 2 hf0
  • 4 hf0
  • 3 hf0
  • hf0/ 2
Sodium surface is illuminated by ultraviolet and visible radiation successively and the stopping potential determined. The stopping potential is
  • Greater with visible light
  • Equal in both cases
  • Greater with ultraviolet light
  • Infinite in both cases
Light of frequency 1.5 times the threshold frequency is incident on a photosensitive material .If the frequency is halved and the intensity is doubled, the photoelectric current becomes
  • Doubled
  • Quadrupled
  • Halved
  • zero
Light of wavelength 4000 Ao is incident on a metal of work function 3.2 x 10-19 J. What is the maximum kinetic energy of the emitted electron?
  • 2.2 x 10-19 J
  • 1.75 x 10-19 J
  • 0.75 x 10-19 J
  • 1.1 x 10-19 J
Light from a bulb is falling on a wooden table but no photo electrons are emitted as
  • Work function of wood is less
  • Work function of wood is more
  • It depends on the frequency
  • It is independent of work function
Photons of energy 6 eV are incident on a potassium surface of a work function 2.1 eV. What is the stopping potential?
  • -3.9V
  • -8.1V
  • -5V
  • -1.9V
The energy of the incident photon is 20 eV and the work function of the photosensitive metal is 10 eV. What is the stopping potential?
  • 30 V
  • 5 V
  • 10 V
  • 15 V
Light of two different frequencies whose photons have energies of 1eV and 2.5 eV respectively successively illuminate a metal of work function 0.5eV. The ratio of maximum speed of emitted electrons is
  • 1:5
  • 1:4
  • 1:3
  • 1:2
A photosensitive material would emit electrons if exited by photons beyond a threshold. To cross the threshold, you would increase
  • Frequency of light
  • Wavelength of light
  • Intensity of light
  • Amplitude of light
0 h : 0 m : 1 s

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