$A$ point source causes the photoelectric effect from a small metal plate. Which of the following curves may represent the saturation photocurrent $(I)$ as a function of the distance $(r)$ between the source and the metal?

If the frequency of incident radiation is kept constant and the experiment is repeated by using incident light of different intensities,then the stopping potential $(V_{s})$

The wave picture of light has failed to explain which of the following phenomena?

Threshold frequency for a metal is $15 \times 10^{14} \, Hz$. The light of wavelength $6000 \, \text{Å}$ falls on the metal surface. Then photoelectrons [velocity of light in air, $c = 3 \times 10^8 \, m/s$]:

The minimum energy required to remove an electron from the surface of a metal is called:

$A$ 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 $= 5\,cm^2$)