The wavelengths of light incident on a photocell are $400 \ nm$ and $250 \ nm$. The velocities of the emitted photoelectrons are $v$ and $2v$ respectively. What is the work function of the metal?

Photons of energy $2.4 \text{ eV}$ and wavelength $\lambda$ fall on a metal plate and release photoelectrons with a maximum velocity $v$. By decreasing $\lambda$ by $50 \%$, the maximum velocity of photoelectrons becomes $3 v$. The work function of the material of the metal plate is (in $\text{ eV}$)

The graph of stopping potential $V_s$ against frequency $\nu$ of incident radiation is plotted for two different metals $X$ and $Y$ as shown in the graph. If $\phi_x$ and $\phi_y$ are the work functions of $X$ and $Y$,respectively,then:

In the graph given below,if the slope is $4.12 \times 10^{-15} \ V-sec$,then the value of $h$ should be:

Which theory of light can explain the photoelectric effect?

The work function of a metal is $2.51 \ eV$. What is its threshold frequency?