Which graph represents the relationship between the intensity of incident light on a metal plate and the resulting photoelectric current?

When yellow light is incident on a surface,no electrons are emitted,while green light can emit them. If red light is incident on the surface,then:

Assertion : Kinetic energy of photoelectrons emitted by a photosensitive surface depends upon the intensity of incident photon.
Reason : The ejection of electrons from a metallic surface is possible with a frequency of incident photon below the threshold frequency.

$A$ 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?

When an inert gas is filled in the place of vacuum in a photo cell,then

When a monochromatic point source of light is at a distance of $0.2\, m$ from a photoelectric cell,the cut-off voltage and the saturation current are respectively $0.6\, V$ and $18.0\, mA$. If the same source is placed $0.6\, m$ away from the photoelectric cell,then