During a photoelectric effect experiment,which of the following physical quantities depends on the intensity of the incident radiation?

$A$ photosensitive material is at $9\,m$ to the left of the origin and the source of light is at $7\,m$ to the right of the origin along the $x$-axis. The photosensitive material and the source of light start from rest and move,respectively,with $8\widehat{i}\,m/s$ and $4\widehat{i}\,m/s$. The ratio of intensities at $t = 0$ to $t = 3\,s$ as received by the photosensitive material is:

The work function of aluminium is $4.2 \ eV$. If two photons, each of energy $3.5 \ eV$, strike an electron of aluminium, then the emission of electrons will be:

The figure represents the graph of photoelectric current $I$ versus applied voltage $(V)$. The maximum kinetic energy of the emitted photoelectrons is

$A$ small metal ball is suspended in a uniform electric field with the help of an insulated thread. If a high energy $X-$ray beam falls on the ball,then the ball

The quantum nature of light is explained by which of the following phenomena?