Light of wavelength $4000 Å$ is incident on a sodium surface for which the threshold wavelength of photoelectrons is $5420 Å$. The work function of sodium is (in $eV$)

Light with a frequency of $1.5$ times the threshold frequency is incident on a photosensitive material. If the frequency is halved and the intensity is doubled,what will be the photoelectric current?

The graph shows the variation of photocurrent with anode potential for four different radiations. Let $I_a, I_b, I_c$ and $I_d$ be the intensities and $f_a, f_b, f_c$ and $f_d$ be the frequencies for the curves $a, b, c$ and $d$ respectively,then

$A$ point source of light is used in an experiment of photoelectric effect. If the distance between the source and the photoelectric surface is doubled, which of the following may result?

Consider the two following statements $A$ and $B$ and identify the correct choice given in the answers:

For a given source,with an increase in intensity of incident radiation,the . . . . . .