The ratio of momenta of an electron and α-particle which are accelerated from rest by a
potential difference of 100 V is :

The threshold frequency for a photosensitive metal is \[3.3\times 10^{14} Hz\]. If light of frequency \[8.2\times 10^{14} Hz\] is incident on this metal, the cut-off voltage for the photoelectric emission is nearly :

When a point source of monochromatic light is at a distance of 0.2 m from a photoelectric cell, the cut-off voltage and the saturation current are 0.6 volt and 18 mA respectively. If the same source is placed 0.6 m away from the photoelectric cell, then :

The figure shows different graphs between stopping potential (V0) and frequency (n) for photosensitive surface of caesium, potassium, sodium and lithium. The plots are parallel. Correct ranking of the targets according to their work function, greatest first, will be :

The energy that should be added to an electron to reduce its de Broglie wavelength from

\[10^{-10}m\]  to \[0.5\times 10^{-10}m\] m will be :

The velocity of the most energetic electrons emitted from a metallic surface is doubled when the frequency v of the incident radiation is doubled. The work function of this metal is :

Monochromatic light of frequency f1 is incident on a photocell and the stopping potential is found to be V1. What is the new stopping potential of the cell if it is radiated by monochromatic light of frequency f2 ?

The correct graph between the maximum energy of a photoelectron and the inverse of wavelength of the incident radiation is given by the curve

A photon of wavelength 6630 Å is incident on a totally reflecting surface. The momentum delivered by the photon is equal to

The ratio of de-Broglie wavelengths of molecules of hydrogen and helium which are at temperature 27°C and 127° respectively is :