NEET UG PHYSICS MCQ: ELECTROMAGNETIC WAVES

1 Medium

1 of 1

Application +4 | -1

An electromagnetic wave propagates in a medium, whose electric field vector is given as

E = 200\sin \left( {18 \times {{10}^8}t + 8x} \right)\,V\,{m^{ - 1}}

. Refractive index of medium and amplitude of magnetic field will be

View answer and explanation

Correct option: D

\mu = \frac{4}{3};\,{B_0} = \frac{8}{9} \times {10^{ - 6}}T

Option D (

\mu = \frac{4}{3};\,{B_0} = \frac{8}{9} \times {10^{ - 6}}T

) is correct because the refractive index is the ratio of the speed of light in vacuum to the speed of light in the medium, and the amplitude of the magnetic field is the amplitude of the electric field divided by the speed of light in the medium.

More Questions from ELECTROMAGNETIC WAVES

Practice All Chapter MCQs →

What is order of energy of X-rays (

{E_X}

), radio waves (

{E_R}

) and microwave (

{E_M}

)? The amplitude of the sinusoidally oscillating electric field of plane wave is

60\,\,\frac{V}{m}

. Then the amplitude of the magnetic field is An EM wave from air enters a medium. The electric fields are

{E_1} = {E_{01}}\hat x\cos \left[ {2\pi v\left( {\frac{z}{c} - t} \right)} \right]

in air and

{E_2} = {E_{02}}\hat x\cos \left[ {k\left( {2z - ct} \right)} \right]

in medium, where the wave number k and frequency ν refer to their values in air. The medium is non-magnetic.
If

{\varepsilon _{{r_1}}}

and

{\varepsilon _{{r_2}}}

refer to relative permittivities of air and medium respectively, which of the following options is correct? Electric field in a plane electromagnetic wave is given by

E = 50\sin \,(500x - 10 \times {10^{10}}t)\,v/m.

The velocity of electromagnetic wave in this medium is
(Given,

c

= speed of light in vacuum) If an electromagnetic wave is propagation in a medium with permeability 

\mathrm{\varepsilon }

and permittivity

\mathrm{\mu }

, then

\sqrt {\frac{\mathrm{\mu }}{\mathrm{\varepsilon }}}

is the In an E.M. wave the average energy density is associated with:-