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

Define the work function of a metal and write its unit.

Threshold frequency for a metal is $15 \times 10^{14} \, Hz$. The light of wavelength $6000 \, \text{Å}$ falls on the metal surface. Then photoelectrons [velocity of light in air, $c = 3 \times 10^8 \, m/s$]:

The figure 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 for the curves $a, b, c$ and $d$ respectively $[f_a, f_b, f_c$ and $f_d$ are frequencies respectively].

On a photosensitive surface, if the intensity of incident radiation is increased, the stopping potential

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