The maximum kinetic energy of photoelectrons emitted from a surface when photons of energy 6 eV fall on it is 4 eV. The stopping potential in volt is
2
4
6
10
Which of the following is a correct statement?
Beta rays are same as cathode rays
Gamma rays are high energy neutrons
Alpha particles are singly ionised helium atoms
Protons and neutrons have exactly the same mass
The threshold wavelength for photoelectric emission from a material is 5200 A. photoelectric emission from a material is illuminated with monochromatic radiation from a
50 watt infrared lamp
I-watt infra-red lamp
50 watt ultraviolet lamp
I-watt ultraviolet lamp
Photoelectric effect supports quantum nature of light because:
There is a minimum frequency of light below which no photoelectron are emitted
The maximum kinetic energy of photo electron depends only on the frequency of light and not on its intensity.
Even when the metal surface is faintly illuminated, the photoelectrons leave the surface immediately.
Electric charge of the photoelectrons is quantized.
1, 2 and 3
2, 3 and 4
When a monochromatic point source of light is at a distance of 0.2 m from a photoelectric cell, the cut off voltage and the saturation current are respectively 0.6 V an 18.0 mA. If the same source is placed 0.6 m away from the photoelectric cell, then
The stopping potential will be 0.2 volt
The stopping potential will be 0.6 volt
The saturation current will be 6.0 mA
The saturation current will be 2.0 mA
1 and 3
2 and 4
When photons of energy 4.25 eV strike the surface of metal A, the ejected photoelectrons have maximum kinetic energy. TA eV and be broglie wavelength (A. The maximum kinetic energy of photoelectrons liberated from another metal B by photons of energy 4.70 eV is TB= (TA-1.50)eV. If the be Broglie wavelength of these photoelectrons is (B=2(A. then
The work function of A is 2.25 eV
The work function of B is 4.20 eV.
TA =2.00 eV.
TB= 2.75 eV
1, 2 and 3
2, 3 and 4
The work function of a substance is 4.0 eV. The longest wavelength of light that can cause photoelectron emission from this substance is approximately
540 nm
400 nm
310 nm
220 nm