During a photoelectric effect experiment,which of the following physical quantities depends on the intensity of the incident radiation?

The figure shows the variation of photocurrent $i$ with anode potential $V$ 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. Then

Explain the effect of the frequency of incident radiation in the experiment of the photoelectric effect.

In a photoelectric experiment,a parallel beam of monochromatic light with power of $200 \ W$ is incident on a perfectly absorbing cathode of work function $6.25 \ eV$. The frequency of light is just above the threshold frequency so that the photoelectrons are emitted with negligible kinetic energy. Assume that the photoelectron emission efficiency is $100 \%$. $A$ potential difference of $500 \ V$ is applied between the cathode and the anode. All the emitted electrons are incident normally on the anode and are absorbed. The anode experiences a force $F = n \times 10^{-4} \ N$ due to the impact of the electrons. The value of $n$ is. . . . .
Mass of the electron $m_e = 9 \times 10^{-31} \ kg$ and $1.0 \ eV = 1.6 \times 10^{-19} \ J$.

$A$ 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:

Which figure shows the correct variation of applied potential difference $(V)$ with photoelectric current $(I)$ at two different intensities of light $(I_1 < I_2)$ of the same wavelength?