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

Radiation of intensity $I$ is falling obliquely on a surface. The area of the surface exposed to radiation is $A$. The angle of incidence with the normal is $\theta$. Select the correct alternative,where $\beta$ is a constant that depends upon the nature of the surface.

Average force exerted on a non-reflecting surface at normal incidence is $2.4 \times 10^{-4} \,N$. If $360 \,W/cm^2$ is the light energy flux during a span of $1$ hour $30$ minutes,then the area of the surface is: (in $\,m^2$)

Professor $C.V.$ Raman surprised his students by suspending a tiny light ball in a transparent vacuum chamber by shining a laser beam on it. Which property of $EM$ waves was he exhibiting? Give one more example of this property.

$A$ point source of light is placed at the centre of curvature of a hemispherical surface. The source emits a power of $24 \, W$. The radius of curvature of the hemisphere is $10 \, cm$ and the inner surface is completely reflecting. The force on the hemisphere due to the light falling on it is $.......... \times 10^{-8} \, N$.

$A$ lamp delivers a luminous flux of $100 \,W$ to an absorber of area $1 \,cm^2$. The force due to radiation pressure is