The threshold wavelength for the emission of photoelectrons from a material is $5200\, \text{\AA}$. Which of the following monochromatic light sources will cause the emission of photoelectrons from this surface?

The correct curve between the stopping potential $(V_0)$ and intensity of incident light $(I)$ is

The cathode of a photocell is changed such that the work function changes from $w_1$ to $w_2$ $(w_2 > w_1)$. If the saturation currents before and after the change are $I_1$ and $I_2$ respectively,and all other conditions (such as incident light intensity and frequency) remain unchanged,then (assuming $h\nu > w_2$):

Given below are two statements: one is labelled as Assertion $A$ and the other is labelled as Reason $R$.
Assertion $A :$ In photoelectric effect,on increasing the intensity of incident light,the stopping potential increases.
Reason $R :$ Increase in intensity of light increases the rate of photoelectrons emitted,provided the frequency of incident light is greater than threshold frequency.
In the light of the above statements,choose the correct answer from the options given below:

When an inert gas is filled in the place of vacuum in a photo cell,then

The maximum value of the stopping potential in the following diagram is .......... $V$.