The energy of the X-rays photon is 3.3$\times {10}^{-16}$J. Its frequency is :

(1) $2\times {10}^{19} Hz$

(2) $5\times {10}^{18} Hz$

(3) $5\times {10}^{17} Hz$

(4) $5\times {10}^{16} Hz$

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) ${10}^7 W$