A plane E M wave of frequency 25 MHz travels in free space in the x-direction. At a particular point in space and time $E=6.3 \hat{j} V/m$ then B at the point is 

(1) $2.1\times {10}^{-8} -\hat{k}$

(2) $2.1\times {10}^{-8} \hat{k}$

(3) 2.1 $\hat{k}$

(4) $2.1\times {10}^{-8} \hat{i}$

In an electromagnetic wave, the amplitude of the electric field is \(1~\text{V/m}.\) The frequency of a wave is \(5\times 10^{14}~\text{Hz}.\) The wave is propagating along the \(z\text-\)axis. The average energy density of the electric field in \(\text{J/m}^3,\) will be:
1. \(2.2\times 10^{-12}\)
2. \(4.4\times 10^{-12}\)
3. \(6.6\times 10^{-12}\)
4. \(8.8\times 10^{-12}\)

The infra-red spectrum lies between :

(1) radio wave and microwave region

(2) the micro-wave and visible region

(3) the visible and ultraviolet region

(4) the ultraviolet and the X-ray region

Which of the following electromagnetic waves has minimum frequency?
1. Radio waves
2. Infrared waves
3. Microwaves
4. X-rays

A lamp emits monochromatic green light uniformly in all directions. The lamp is \(3\%\) efficient in converting electrical power to electromagnetic waves and consumes \(100\) W of power. The amplitude of the electric field associated with the electromagnetic radiation at a distance of \(5\) m from the lamp will be:
1. \(1.34\) V/m
2. \(2.68\) V/m
3. \(4.02\) V/m
4. \(5.36\) V/m

A parallel plate capacitor consists of two circular plates each of radius 2 cm, separated by a distance of 0.1 mm. If the voltage across the plates is varying at the rate of $5\times {10}^{13}$ V/s, then the value of displacement current is :

(1) 5.50 A

(2) $5.56\times {10}^2 A$

(3) 5.56$\times {10}^3$ A

(4) $2.28\times {10}^4 A$

In an electromagnetic wave, the direction of the magnetic field induction $\overrightarrow{B}$ is

(1) parallel to electric field $\overrightarrow{E}$

(2) perpendicular to electric field $\overrightarrow{E}$

(3) antiparallel to Poynting vector $\overrightarrow{S}$

(4) random

In an electromagnetic wave

(1) Power is transmitted along the magnetic field

(2) Power is transmitted along the electric field

(3) Power is equally transferred along with the electric and magnetic fields

(4) power is transmitted in a direction perpendicular to both the fields