Dual Nature of Radiation and Matter · Question 26

The photoelectric threshold wavelength of silver is 3250 10-10 m. The velocity of the electron ejected from a silver surface by ultraviolet light of wavelength 2536 10-10 m is [Given h = 4.14 10-15 eV s and c = 3 108 m s-1]

1. 0.6 106 m s-1
2. 61 103 m s-1
3. 0.3 106 m s-1
4. 6 105 m s-1

An electron of mass m and a photon have same energy E. The ratio of de-Broglie wavelengths associated with them is

1. c(2mE) 12
2. 1c ( 2mE ) 12
3. 1c ( E2m ) 12
4. ( E2m ) 12

When a metallic surface is illuminated with radiation of wavelength , the stopping potential is V. If the same surface is illuminated with radiation of wavelength 2 , the stopping potential is V4. The threshold wavelength for the metallic surface is

1. 52
2. 3
3. 4
4. 5

Photons with energy 5 eV are incident on a cathode C in a photoelectric cell. The maximum energy of emitted photoelectrons is 2 eV. When photons of energy 6 eV are incident on C, no photoelectrons will reach the anode A, if the stopping potential of A relative to C is

1. +3 V
2. +4 V
3. -1 V
4. -3 V

A photoelectric surface is illuminated successively by monochromatic light of wavelength and /2. If the maximum kinetic energy of the emitted photoelectrons in the second case is 3 times that in the first case, the work function of the surface of the material is (h = Planck's constant, c = speed of light)

1. 2hc
2. hc3
3. hc2
4. hc

Light of wavelength 500 nm is incident on a metal with work function 2.28 eV. The de Broglie wavelength of the emitted electron is

1. 2.8 10-9 m
2. 2.8 10-12 m
3. < 2.8 10-10 m
4. < 2.8 10-9 m

Which of the following figures represent the variation of particle momentum and the associated de-Broglie wavelength?

1. [figure]
2. [figure]
3. [figure]
4. [figure]

A certain metallic surface is illuminated with monochromatic light of wavelength, . The stopping potential for photo-electric current for this light is 3V0. If the same surface is illuminated with light of wavelength 2 , the stopping potential is V0. The threshold wavelength for this surface for photo-electric effect is

1. 4
2. 6
3. 6
4. 4

When the energy of the incident radiation is increased by 20%, the kinetic energy of the photoelectrons emitted from a metal surface increased from 0.5 eV to 0.8 eV. The work function of the metal is

1. 0.65 eV
2. 1.0 eV
3. 1.3 eV
4. 1.5 eV

If the kinetic energy of the particle is increased to 16 times its previous value, the percentage change in the de Broglie wavelength of the particle is

1. 25
2. 75
3. 60
4. 50