Physics Crash Course JEE Main>Chapter 17 - Electromagnetic Waves>Level 2>Q 2

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JEE Main

IMPORTANT

Earn 100

An electromagnetic wave of frequency $5 GHz$ is travelling in a medium whose relative electric permittivity and relative magnetic permeability both are $2 .$ Its velocity in this medium is $. . . . . . . \times 10^{7} m / s$

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Important Questions on Electromagnetic Waves

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JEE Main

IMPORTANT

Physics Crash Course JEE Main>Chapter 17 - Electromagnetic Waves>Level 2>Q 3

For radiation of

9 GHz

passing through air. The number of waves passing through

1 m

length is

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JEE Main

IMPORTANT

Physics Crash Course JEE Main>Chapter 17 - Electromagnetic Waves>Level 2>Q 4

A light beam travelling in the

x -

direction is described by the electric field

E_{y} = (300 V m^{- 1}) \sin [ω (t - \frac{x}{c})]

. The maximum magnetic field is

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JEE Main

IMPORTANT

Physics Crash Course JEE Main>Chapter 17 - Electromagnetic Waves>Level 2>Q 5

An electromagnetic radiation of frequency

v

, wavelength

λ

travelling with velocity

c

in air enters a glass slab of refractive index

μ

. The frequency, wavelength and velocity in the glass slab will be, respectively,

EASY

JEE Main

IMPORTANT

Physics Crash Course JEE Main>Chapter 17 - Electromagnetic Waves>Level 2>Q 6

The wavelength of electromagnetic waves employed for space communication lie in the range of-

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JEE Main

IMPORTANT

Physics Crash Course JEE Main>Chapter 17 - Electromagnetic Waves>Level 2>Q 7

The sound waves after being converted into electrical waves are not transmitted as such because -

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Physics Crash Course JEE Main>Chapter 17 - Electromagnetic Waves>Level 2>Q 8

If

n_{R}

and

n_{V}

denote the number of photons emitted by a red bulb and violet bulb of equal power in a given time, then

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JEE Main

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Physics Crash Course JEE Main>Chapter 17 - Electromagnetic Waves>Level 2>Q 9

Intensity of radiation at surface of sun is

10^{8} W m^{- 2} .

RMS value of magnetic induction is

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IMPORTANT

Physics Crash Course JEE Main>Chapter 17 - Electromagnetic Waves>Level 2>Q 10

Assume a bulb of efficiency

2.5 %

as a point source. The peak values of electric and magnetic fields produced by the radiation coming from a

100 W

bulb at a distance of

3 m

is respectively