In a photo cell,the photo-electrons emission takes place

The figure shows the variation of photocurrent with anode potential for a photo-sensitive surface for three different radiations. Let ${I_a}, {I_b}$ and ${I_c}$ be the intensities and ${f_a}, {f_b}$ and ${f_c}$ be the frequencies for the curves $a, b$ and $c$ respectively.

$A$ source of variable potential difference is connected across a photoelectric cell, and the photoelectric current is plotted against the applied potential difference. The graph with the broken line represents the initial curve of current versus applied potential difference. If the frequency of the incident light is increased and its intensity is reduced, which curve now represents the situation?

The curves $(1)$,$(2)$,$(3)$,and $(4)$ show the variation between the applied potential difference $(V)$ and the photoelectric current $(i)$ at two different intensities of light $(I_1 > I_2)$. In which figure is the correct variation shown?

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

In the photoelectric effect,the photocurrent: