NEET UG PHYSICS MCQ: ELECTROMAGNETIC WAVES

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Application +4 | -1

In a uniform magnetic field of

{10^{ - 5}}T

in free space, the energy density is u. The electric field which will produce the same energy density in free space is

View answer and explanation

Correct option: B

3 \times {10^3}V/m

Option B (

3 \times {10^3}V/m

) is correct because it equates the energy density of the magnetic field to the energy density of the electric field and solves for the electric field strength.

More Questions from ELECTROMAGNETIC WAVES

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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:-