Electromagnetic radiation of intensity $0.6 \ W/m^2$ is falling on a black surface. The radiation pressure on the surface is

$A$ radiation of energy $E$ falls normally on a perfectly reflecting surface. The momentum transferred to the surface is ($C =$ velocity of light).

Light with an average flux of $20 \, W/cm^2$ falls on a non-reflecting surface at normal incidence having a surface area of $20 \, cm^2$. The energy received by the surface during a time span of $1 \, minute$ is $............ \, J$.

The radiation of energy $E$ falls normally on a perfectly reflecting surface. The momentum transferred to the surface is

$A$ bulb of $800 \text{ W}$ electrical power has an efficiency of $3 \%$. It is kept at the centre of a sphere of diameter $20 \text{ cm}$. The force exerted on its surface by the electromagnetic $(EM)$ wave is . . . . . . .

$A$ small mirror of mass $m$ is suspended by a massless thread of length $l$. Find the small angle through which the thread will be deflected when a short pulse of laser of energy $E$ falls normally on the mirror. ($c=$ speed of light in vacuum and $g=$ acceleration due to gravity)