The work function of a metal is

The number of photo-electrons emitted per second from a metal surface increases when:

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?

If the frequency of incident radiation is kept constant and the experiment is repeated by using incident light of different intensities,then the stopping potential $(V_{s})$

Define threshold frequency and on which factor does threshold frequency depend?

Which of the following statements is correct?