Which scientist discarded postulate of ether? 

If a source is transmitting electromagnetic wave of frequency $8.2 \times {10^6}Hz$, then wavelength of the electromagnetic waves transmitted from the source will be.....$m$

What is radiation pressure ? 

The electric field of a plane electromagnetic wave propagating along the $x$ direction in vacuum is $\overrightarrow{ E }= E _{0} \hat{ j } \cos (\omega t - kx )$. The magnetic field $\overrightarrow{ B },$ at the moment $t =0$ is :

If the magnetic field of a plane electromagnetic wave is given by (The speed of light $ = 3 \times {10^8}\,m/s$ )

$B = 100 \times {10^{ - 6}}\,\sin \,\left[ {2\pi  \times 2 \times {{10}^{15}}\,\left( {t - \frac{x}{c}} \right)} \right]$ 

then the maximum electric field associated with it is

The magnetic field of a plane electromagnetic wave is given by

$\vec B\, = {B_0}\hat i\,[\cos \,(kz - \omega t)]\, + \,{B_1}\hat j\,\cos \,(kz - \omega t)$ where ${B_0} = 3 \times {10^{-5}}\,T$ and ${B_1} = 2 \times {10^{-6}}\,T$. The rms value of the force experienced by a stationary charge $Q = 10^{-4} \,C$ at $z = 0$ is closet to