A plane electromagnetic wave propagating along y-direction can have the following pair of electric field $(\vec{E} )$ and magnetic field $(\overrightarrow{ B })$ components.

In a certain region uniform electric field $E$ and magnetic field $B$ are present in the opposite direction. At the instant $t = 0,$ a particle of mass $m$ carrying a charge $q$ is given velocity $v_o$ at an angle $\theta ,$ with the $y$ axis, in the $yz$ plane. The time after which the speed of the particle would be minimum is equal to

If radiation is totally absorbed and energy incident on surface in time $t$ be $U$ then write equation of momentum imparted to surface. 

A plane $EM$ wave travelling along $z-$ direction is described$\vec E = {E_0}\,\sin \,(kz - \omega t)\hat i$ and $\vec B = {B_0}\,\sin \,(kz - \omega t)\hat j$. Show that

$(i)$ The average energy density of the wave is given by $U_{av} = \frac{1}{4}{ \in _0}E_0^2 + \frac{1}{4}.\frac{{B_0^2}}{{{\mu _0}}}$

$(ii)$ The time averaged intensity of the wave is given by  $ I_{av}= \frac{1}{2}c{ \in _0}E_0^2$ વડે આપવામાં આવે છે.

A plane electromagnetic wave of wave intensity $6\,W/m^2$ strike a small mirror of area $30\,cm^2$ , held perpendicular to a approching wave. The momentum transmitted in $kg\, m/s$ by the wave to the mirror each second will be

Light is an electromagnetic wave. Its speed in vacuum is given by the expression