When a photon of light collides with a metal surface, the number of electrons (if any) coming out is:

Albert Einstein was awarded the Nobel Prize in Physics for his work on

All electrons ejected from a metallic surface by incident light of wavelength $400 \,nm$ travelled $1 \,m$ in the direction of a uniform electric field of $2 \,N/C$ and came to rest. The work function of the surface is (in $\,eV$)

$A$ light of wavelength $310 \,nm$ is used in a photoelectric experiment. The metal electrode of work function $2.5 \,eV$ is used in the experiment. The stopping potential for the photoelectrons will be (assume $hc = 1240 \,eV-nm$): (in $V$)

Light of wavelength $3500 \ \mathring A$ is incident on two metals $A$ and $B$. If their work functions are $4.2 \ eV$ and $1.9 \ eV$ respectively,which metal will emit photoelectrons?

In the case of the photoelectric effect,the graph of measured stopping potential $(V_0)$ against the frequency $(\nu)$ of incident light is a straight line. The slope of this line multiplied by the charge of an electron $(e)$ gives: