Physics - Modern Physics Question with Solution | TestHub

From the given graph, all four curves (a, b, c, and d) meet at the same point on the retarding potential axis. This indicates that they all have the same stopping potential ($V_0$).

The stopping potential depends on the frequency of the incident radiation. Since the stopping potential is the same for all curves, the frequencies of the incident radiations must be equal. Therefore, $f_a=f_b=f_c=f_d$.

The saturation photocurrent is represented by the maximum constant value of the current on the accelerating potential axis. From the graph, the saturation currents are in the order of the curves d, c, b, and a as $I_d>I_c>I_b>I_a$.

Since the saturation photocurrent is directly proportional to the intensity of the incident radiation, the intensities must follow the same order. Therefore, $I_a<I_b<I_c<I_d$.

Answer: ${\mathrm{f}}_{\mathrm{a}}={\mathrm{f}}_{\mathrm{b}}={\mathrm{f}}_{\mathrm{c}}={\mathrm{f}}_{\mathrm{d}}$ and ${\mathrm{I}}_{\mathrm{a}}<{\mathrm{I}}_{\mathrm{b}}<{\mathrm{I}}_{\mathrm{c}}<{\mathrm{I}}_{\mathrm{d}}$