The book “Physics of Physics” was written by

The anode voltage of a photocell is kept constant. The wavelength of the incident light on the cathode is changed gradually. Then,the photoelectric current $I$ of the photocell varies according to which of the following graphs?

Unification of weak and electromagnetic interactions was done by

The de-Broglie wavelength of an electron is the same as that of a photon. If the velocity of the electron is $25 \%$ of the velocity of light,then the ratio of the $K.E.$ of the electron to the $K.E.$ of the photon will be:

The graph shows the stopping potential as a function of the frequency of incident radiation for two different surfaces $A$ and $B$. The work function of surface $A$ is ......

The particle nature and wave nature of electromagnetic waves and electrons can be demonstrated by which of the following?