The speed of an electromagnetic wave in a vacuum depends upon the source of radiation.

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 electric field for a plane electromagnetic wave travelling in the $+y$ direction is shown in the figure. Consider a point where the electric field is in the $+z$ direction. The magnetic field $\vec B$ is

The electric field in an electromagnetic wave is given as $\vec{E} = 20 \sin \omega (t - \frac{x}{c}) \hat{j} \text{ N/C}$. Where $\omega$ and $c$ are the angular frequency and velocity of the electromagnetic wave,respectively. The energy contained in a volume of $5 \times 10^{-4} \text{ m}^3$ will be $..... \times 10^{-13} \text{ J}$. (Given $\varepsilon_0 = 8.85 \times 10^{-12} \text{ C}^2/\text{Nm}^2$)

If $\vec{E}$ and $\vec{B}$ are the electric and magnetic field vectors of an electromagnetic wave,then the direction of propagation of the electromagnetic wave is

$A$ charged particle oscillates about its mean equilibrium position with a frequency of $10^{9} \,Hz$. The frequency of electromagnetic waves produced by the oscillator is . . . . . . .