In Lenard's experiment,what is the effect on the photoelectric current when ultraviolet radiation incident on the cathode is stopped?

The work functions of Caesium $(Cs)$, Potassium $(K)$, and Sodium $(Na)$ are $2.14 \ eV$, $2.30 \ eV$, and $2.75 \ eV$ respectively. If incident electromagnetic radiation has an incident energy of $2.41 \ eV$, which of these photosensitive surfaces may emit photoelectrons?

Consider the two following statements $A$ and $B$ and identify the correct choice given in the answers:

When yellow light is incident on a surface,no electrons are emitted,while green light can emit them. If red light is incident on the surface,then:

Which of the following is dependent on the intensity of incident radiation in a photoelectric experiment?

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