Light from the Paschen series of a hydrogen atom is able to eject photoelectrons from a metal. Then the work function of the metal is:

The work function of caesium is $2.14 \ eV$. Find the wavelength of the incident light if the photocurrent is brought to zero by a stopping potential of $0.60 \ V$. (Answer in $nm$)

Photons of wavelength $\lambda$ emitted by a source of power $P$ are incident on a photocell. If the current produced in the cell is $I$,then the percentage of incident photons which produce current in the photocell is: (where $h$ is Planck's constant and $c$ is the speed of light in vacuum)

If the stopping potential of photoelectrons emitted by a source placed at a distance of $0.2 \ m$ from a photocell is $0.6 \ V$,then the stopping potential of photoelectrons emitted by the same source placed at a distance of $0.6 \ m$ from the photocell will be .......... $V$.

Light comprising three wavelengths $310 \ nm$,$455 \ nm$,and $620 \ nm$ is incident on a surface separating two media at an angle of $45^o$. The refractive index for the $455 \ nm$ light is $\sqrt{2}$. If a metal plate with a work function of $1.2 \ eV$ is placed in the second medium,what is the maximum kinetic energy of the electrons emitted from the metallic plate in $eV$?

The work function of a metal is $1 \; eV$. Light of wavelength $3000 \; \mathring{A}$ is incident on this metal surface. The velocity of the emitted photo-electrons will be: