What is the intensity of radiation (light)?

Give an outline of the experimental study of the photoelectric effect.

The work function of a metal is

The threshold frequency for a metal is $10^{15} \ Hz$. Choose the correct statement when light of wavelength $4000 \ \mathring A$ is incident on it.

Define threshold frequency.

From the photoelectric effect experiment, the following observations are made. Identify which of these are correct:
$A.$ The stopping potential depends only on the work function of the metal.
$B.$ The saturation current increases as the intensity of incident light increases.
$C.$ The maximum kinetic energy of a photoelectron depends on the intensity of the incident light.
$D.$ The photoelectric effect can be explained using the wave theory of light.
Choose the correct answer from the options given below: