If a source is transmitting an electromagnetic wave of frequency \(8.2\times 10^{6}~\text{Hz}\), then the wavelength of the electromagnetic wave transmitted from the source will be:

1.	\(36.6\) m	2.	\(40.5\) m
3.	\(42.3\) m	4.	\(50.9\) m

A plane electromagnetic wave $E_z=100 \cos (6\times {10}^{8}t+4x) V/m$ propagates in a medium of dielectric constant

(1) 1.5

(2) 2.0

(3) 2.4

(4) 4.0

If ${\mu }_0$ be the permeability and $K_0$ the dielectric constant of a medium, its refractive index is given by

(1) $\frac{1}{\sqrt{{\mu }_0{K}_0}}$

(2) $\frac{1}{{\mu }_0{K}_0}$

(3) $\sqrt{K_0}$

(4) ${\mu }_0{K}_0$

If \(\varepsilon_0~\text{and}~\mu_0\) represent the permittivity and permeability of vacuum and \(\varepsilon~\text{and}~\mu\) represent the permittivity and permeability of the medium, the refractive index of the medium is given by:

The magnetic field between the plates of radius 12 cm separated by a distance of 4 mm of a parallel plate capacitor of capacitance 100 pF along the axis of plates having conduction current of 0.15 A is

(1) zero

(2) 1.5 T

(3) 15 T

(4) 0.15 T

A flood light is covered with a fitter that transmits red light. The electric field of the emerging beam is represented by a sinusoidal plane wave

$E_x=36 \sin (1.20\times {10}^7 z-3.6\times {10}^{15} t) V/m$

The average intensity of beam in W/$m^2$ will be

(1) 6.88 

(2) 3.44

(3) 1.72

(4) 0.86

A larger parallel plate capacitor, whose plates have an area of 1 $m^2$ are separated from each other by 1 mm, is being charged at a rate of 25.8 V/s. If the plates has dielectric constant 10, then the displacement current at this instant is

(1) 25 $\mu A$

(2) 11 $\mu A$

(3) 2.2 $\mu A$

(4) 1.1 $\mu A$

A parallel plate capacitor with plate area A and separation between the plates d, is charged by a constant current i.  Consider a plane surface of area A/2 parallel to the plates and drawn symmetrically between the plates. The displacement current through this area is

(1) i

(2) i/2

(3) i/4

(4) i/8

The sun delivers ${10}^4 W/m^2$ of electromagnetic flux to the earth's surface. The total power that is incident on a roof of dimensions (10$\times$10) $m^2$ will be

(1) ${10}^4$ W

(2) ${10}^5 W$

(3) ${10}^6 W$

(4) ${10}^7 W$

The wave of wavelength 5900 $\stackrel{0}{A}$ emitted by any atom or molecule must have some finite total length which is known as coherence length. For sodium light, this length is 2.4 cm. The number of oscillations in this length will be

(1) $4.068\times {10}^8$

(2) $4.068\times {10}^4$

(3) $4.068\times {10}^6$

(4) $4.068\times {10}^5$