For a plane electromagnetic wave propagating in $x$-direction, which one of the following combination gives the correct possible directions for electric field $(E)$ and magnetic field $(B)$ respectively?

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 monoenergetic beam of electrons moving along $+ y$ direction enters a region of uniform electric and magnetic fields. If the beam goes straight undeflected, then fields $B$ and $E$ are directed respectively along

An electromagnetic wave of frequency $\nu = 3.0\,MHz$ passes from vacuum into a dielectric medium with permitivity $\varepsilon = 4.0$. Then

An antenna is placed in a dielectric medium of dielectric constant $6.25$. If the maximum size of that antenna is $5.0\, mm$. it can radiate a signal of minimum frequency of $GHz .$

(Given $\mu_{ r }=1$ for dielectric medium)