Light of wavelength $4000 \ \mathring A$ is incident on a photosensitive surface. If a potential of $-2 \ V$ is required to stop the emitted electrons,the work function of the material is: $(h = 6.6 \times 10^{-34} \ J \cdot s, e = 1.6 \times 10^{-19} \ C, c = 3 \times 10^8 \ m/s)$ (in $eV$)

When a metallic surface is illuminated with monochromatic light of wavelength $\lambda$,the stopping potential is $5V_0$. When the same surface is illuminated with light of wavelength $3\lambda$,the stopping potential is $V_0$. Then the work function of the metallic surface is:

Photons with energy $5\, eV$ are incident on a cathode $C$ of a photoelectric cell. The maximum kinetic energy of the emitted photoelectrons is $2\, eV$. When photons of energy $6\, eV$ are incident on $C$,no photoelectrons will reach the anode $A$ if the stopping potential of $A$ relative to $C$ is .............. $V$.

In a photoelectric experiment,the collector plate is at $2.0\,V$ with respect to the emitter plate made of copper $(\phi = 4.5\,eV)$. The emitter is illuminated by a source of monochromatic light of wavelength $200\,nm$.

The stopping potential $(V_s)$ as a function of the frequency $(\nu)$ of the incident radiation is plotted for two different photoelectric surfaces $A$ and $B$. The graphs show that the work function of $A$ is

On a photosensitive material,when the frequency of incident radiation is increased by $20 \%$,the maximum kinetic energy of emitted photoelectrons increases from $0.4 \ eV$ to $0.7 \ eV$. The work function of the material is (in $eV$)