Given below are two statements:

Statement $I$ : Electromagnetic waves are not deflected by electric and magnetic field.

Statement $II$ : The amplitude of electric field and the magnetic field in electromagnetic waves are related to each other as $E _0=\sqrt{\frac{\mu_0}{\varepsilon_0}} B_0$

In the light of the above statements, choose the correct answer from the options given below:

A plane electromagnetic wave of frequency $500\, MHz$ is travelling in vacuum along $y-$direction. At a particular point in space and

time, $\overrightarrow{ B }=8.0 \times 10^{-8} \hat{ z } \;T$. The value of electric field at this point is

(speed of light $\left.=3 \times 10^{8}\, ms ^{-1}\right)$

$\hat{ x }, \hat{ y }, \hat{ z }$ are unit vectors along $x , y$ and $z$ direction.

A velocity selector consists of electric field $\overrightarrow{ E }= E \hat{ k }$ and magnetic field $\overrightarrow{ B }= B \hat{ j }$ with $B =12 mT$.

The value $E$ required for an electron of energy $728 eV$ moving along the positive $x$-axis to pass undeflected is:

(Given, , ass of electron $=9.1 \times 10^{-31} kg$ )

The electric field associated with an em wave in vacuum is given by $\vec{E}=\hat{i} 40 \cos \left(k z-6 \times 10^{8} t\right)$ where $E, x$ and $t$ are in $volt/m,$ meter and seconds respectively. The value of wave vector $k$ is….$ m^{-1}$

During the propagation of electromagnetic waves in a medium