An isolated metallic sphere is illuminated by light of $4\,eV$ photon energy. If the work function of the metal is $2\,eV$,then the minimum potential of the sphere so that no photoelectrons are ejected is ................ $V$.

In a photoelectric effect experiment, the frequency of incident radiation is increased while keeping other factors constant $(f > f_0)$. The stopping potential

In an experiment aimed to disprove Einstein's photoelectric equation,how did Millikan prove it?

The threshold frequency of a metal is $f_0$. When light of frequency $2f_0$ is incident on the metal plate,the maximum velocity of the photoelectrons is $v_1$. When the frequency of the incident radiation is increased to $5f_0$,the maximum velocity of the photoelectrons emitted is $v_2$. The ratio of $v_1$ to $v_2$ is:

The lowest frequency of light that will cause the emission of photoelectrons from the surface of a metal (for which work function is $1.65 \ eV$) will be

When the wavelength of incident radiation is changed from $400 \ nm$ to $310 \ nm$,the maximum kinetic energy of the emitted photoelectrons is doubled. The work function of the metal is ........ $eV$.