$A$ photocell is a device that:

$A$ monochromatic beam of light of wavelength $400\,nm$ is incident normally upon a photosensitive surface ($25\%$ reflects and the rest is absorbed). This produces a radiation pressure of $5 \times 10^{-7}\,N/m^2$ on the surface. If $0.1\%$ of the incident photons produce photoelectrons,the corresponding saturation current will be $\dots \mu A$. (Consider the area of the photosensitive surface $= 5\,cm^2$)

The threshold frequency for a metal is $10^{15} \ Hz$. Choose the correct statement when light of wavelength $4000 \ \mathring A$ is incident on it.

$A$ photoelectric cell is illuminated by a point source of light $1 \ m$ away. When the source is shifted to $2 \ m$,then:

Which of the following statements is correct?

The maximum value of the stopping potential in the following diagram is .......... $V$.