The graph shows the variation of photocurrent with the applied voltage in a photoelectric effect experiment for three different beams of light falling on identical metal surfaces, then which among the following is correct?

The variation of the stopping potential $\left(V_{\circ }\right)$ with the frequency $\left(\nu \right)$ of the light incident on two different photosensitive surfaces M1 and M2 is shown in the figure. Identify the surface which has greater value of the work function.

The following graph represents the variation of photo current with anode potential for a metal surface. Here $I_1, I_2$ and $I_3$ represents intensities and ${\gamma }_1,{\gamma }_2,{\gamma }_3$ represents frequency for curves $1, 2$ and $3$ respectively, then

Define the following with reference to photoelectric effect$:$

$\left(\mathrm{a}\right)$ Threshold frequency $\left(f_o\right)$

Given figure shows few data points in a photo-electric effect experiment for a certain metal. The minimum energy for ejection of electrons from its surface is: (Planck's constant $\mathrm{h}=6.62\times {10}^{–34}\text{ J.s}$)

Define the following with reference to photoelectric effect$:$

$\left(\mathrm{b}\right)$ Stopping potential $\left(V_s\right)$