The radiation pressure exerted by an EM wave of intensity `I` on a black body's surface kept in vacuum is

Options

A. `I//c`
B. `Ic^(2)`
C. `Ic`
D. `I//c^(2)`

Answer

A

Explanation

When a surface intercepts electromagnetic radiation, a force and a pressure are exerted on the surface. As the surface is non - reflecting , so it is completely absorbed and in such case the force is `F = (IA)/(c )`
where `I` is intensity of light .`A` is area of surface and `c` is velocity of electromagnetic wave.
The radiation pressure is the force per unit area
i.e., `p = (F)/(A) = (I)/( c)`