The threshold wavelength for the emission of photoelectrons from a material is $5200\, \text{\AA}$. Which of the following monochromatic light sources will cause the emission of photoelectrons from this surface?

The material of the cathode in a photocell is changed such that the work function of the surface changes from $W_1$ to $W_2$ $(W_2 > W_1)$. If the photocurrents emitted before and after changing the cathode surface are $I_1$ and $I_2$ respectively,and $hf > W_2$,then:

If the intensity of incident light on a metal surface is decreased,then . . . . . .

$A$ photoelectric cell is illuminated by a point source of light kept at a distance $d$. If the distance is reduced to $d/2$,then the number of electrons emitted per second will be:

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:

The minimum energy required to remove an electron from the surface of a metal is called: