In the photoelectric experiment apparatus containing the collector and the emitter plate, a saturated photoelectron current is observed. If an external electric field is applied in the direction opposite to the motion of the photoelectrons, what is the change observed in each of the following? Give reasons.

i. The saturation value of the photocurrent,

ii. The kinetic energy of the photoelectrons striking the collector plate

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 $\left(V_s\right)$