Dual Nature of Radiation MCQ with Answers

Dual Nature of Radiation MCQ with Answers

66) 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 is

Answer is:

4V

Explanation:

Use 1/2mv²_max=hv??_? and W=hV_o

67) A stream of electrons enters an electric field with?10⁷ms^?1?at right angle to it. If the strength of field is?3?10⁴V/m³, the magnetic field acting perpendicular to electric field for producing no deflection of the beam is

Answer is:

3??10^?3T

Explanation:

Use BeV=eE

68) A drop of radius one micron carries a charge of 4 electrons. If the density of oil is 2g/cc, the electric field required to balance it is

Answer is:

12.83??10⁴?V/m

Explanation:

Use BeV=eE

69) When a photon of energy 7eV is made incident on a metal then the emitted electron is stopped by a stopping potential of -5.5V. The work function of metal will be

Answer is:

1.5 eV

Explanation:

Use 1/2mv²_max=hv??_? and W=hV_o

70) In an experiment of photoelectric emission for incident light of 4000?A⁰, the stopping potential is 2V. If the wavelength of incident light is made 3000?A⁰, then stopping potential will be

Answer is:

less than 2 V

Explanation:

Use 1/2mv²_max=hv??_? and W=hV_o