After a photon is incident on a metal surface,the time taken for the emission of a photoelectron from the surface is approximately ...........

Assertion $(A) :-$ The photoelectrons produced by a monochromatic light beam incident on a metal surface have a spread in their kinetic energies.
Reason $(R) :-$ The work function of the metal varies as a function of depth from the surface.

The distance between a light source and a photoelectric cell is $d$. If the distance is decreased to $\frac{d}{2}$, then:

Which figure shows the correct variation of applied potential difference $(V)$ with photoelectric current $(I)$ at two different intensities of light $(I_1 < I_2)$ of the same wavelength?

Define threshold frequency.

The curve between the work function of a metal $(\phi_o)$ and its temperature $(T)$ will be: