For photoelectric emission, tungsten requires light of $2300 \mathring{A}$. If light of $1800 \mathring{A}$ wavelength is incident, then emission:

The curves $(a), (b), (c)$ and $(d)$ show the variation between the applied potential difference $(V)$ and the photoelectric current $(i)$,at two different intensities of light $(I_1 > I_2)$. In which figure is the correct variation shown?

What is the phenomenon of the photoelectric effect?

Which one of the following is true in photoelectric emission?

In a photoelectric effect experiment,light of frequency $1.5$ times the threshold frequency is made to fall on the surface of a photosensitive material. If the frequency is halved and the intensity is doubled,the number of photoelectrons emitted will be:

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