Which of the following does not support the wave nature of light?

Which of the following statements is correct regarding the photoelectric effect?

Light of intensity $10^{-5} \; W m^{-2}$ falls on a sodium photo-cell of surface area $2 \; cm^2$. Assuming that the top $5$ layers of sodium absorb the incident energy,estimate the time required for photoelectric emission in the wave-picture of radiation. The work function for the metal is given to be about $2 \; eV$. What is the implication of your answer?

Define the work function of a metal and write its unit.

Threshold frequency of which of the following metals does not lie in the ultraviolet region (in the case of the photoelectric effect)?

$A$ photoelectric cell is illuminated by a point source of light kept at a distance $d$. If the distance is reduced to $d/2$,then the number of electrons emitted per second will be: