The nature of electromagnetic waves is .......

Assertion $(A):$ $A$ charge moving in a circular orbit can produce electromagnetic waves.
Reason $(R):$ The source of electromagnetic waves should be in accelerated motion.

The ratio of the electric field $(E)$ to the magnetic field $(B)$ in an electromagnetic wave gives which physical quantity?

If the amplitude of the magnetic field part of a harmonic electromagnetic wave in vacuum is $270 \ nT$,the amplitude of the electric field part of the wave is: (in $NC^{-1}$)

$A$ magnetic field vector in an electromagnetic wave is represented by $\vec{B} = B_0 \sin(2\pi vt - \frac{2\pi x}{\lambda}) \hat{j}$. Its associated electric field vector is . . . . . . .

You are driving in your car listening to music on the radio. Your car is equipped with a radio that can receive radio signals of frequency $(f_1 \approx 3 \, MHz)$,$(f_2 \approx 30 \, MHz)$,and $(f_3 = 3 \, GHz)$. You enter a tunnel with a circular opening of diameter $10 \, m$. Which kind of radio signal will you be able to receive for the longest distance as you continue to travel in the tunnel?