Magnetic field in a plane electromagnetic wave is given by, B → = B 0 sin k x + ω t j ^ T . Expression for corresponding electric field will be: (Where c is speed of light)

E → = B 0 c sin k x + ω t k ^ V m - 1

E → = - B 0 c sin k x + ω t k ^ V m - 1

E → = B 0 c sin k x - ω t k ^ V m - 1

E → = B 0 c sin k x + ω t k ^ V m - 1

The magnetic field of an electromagnetic wave is given by: B → = 1.6 × 10 - 6 cos ⁡ 2 × 10 7 z + 6 × 10 15 t 2 i ^ + j ^ W b m 2 The associated electric field will be:

E → = 4.8 × 10 2 c o s 2 × 10 7 z + 6 × 10 15 t - i ^ + 2 j ^ V m

E → = 4.8 × 10 2 c o s 2 × 10 7 z - 6 × 10 15 t - 2 j ^ + i ^ V m

E → = 4.8 × 10 2 c o s 2 × 10 7 z + 6 × 10 15 t i ^ - 2 j ^ V m

E → = 4.8 × 10 2 c o s 2 × 10 7 z - 6 × 10 15 t 2 i ^ + j ^ V m

The electric field of a plane polarized electromagnetic wave in free space at time t = 0 is given by the expression E → x , y = 10 j ^ c o s 6 x + 8 z . The magnetic field B → x , z , t is given by ( c is the velocity of light.)

1 c 6 k ^ - 8 i ^ c o s 6 x + 8 z - 10 c t

1 c 6 k ^ - 8 i ^ cos 6 x + 8 z + 10 c t

1 c 6 k ^ + 8 i ^ cos 6 x + 8 z - 10 c t

1 c 6 k ^ + 8 i ^ cos 6 x - 8 z + 10 c t

The electric field of a plane electromagnetic wave is given by E → = E 0 i ^ c o s k z c o s ( ω t ) The corresponding magnetic field B → is then given by:

B → = E 0 c j ^ sin ⁡ k z s i n ( ω t )

B → = E 0 c j ^ cos ⁡ k z s i n ( ω t )

B → = E 0 c k ^ sin ⁡ k z c o s ( ω t )

B → = E 0 c j ^ sin ⁡ k z c o s ( ω t )

EASY

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The intensity of gamma radiation from a given source is $I_{0}$ . On passing through $37.5 mm$ of lead it is reduced to $\frac{I_{0}}{8}$ . The thickness of lead which will reduce it to $\frac{I_{0}}{2}$ is

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Important Questions on Electromagnetic Waves

EASY

Physics>Modern Physics>Electromagnetic Waves>Nature of Electromagnetic Waves

The magnetic field in a travelling electromagnetic wave has a peak value of

20 nT

. The peak value of electric field strength is :

EASY

Physics>Modern Physics>Electromagnetic Waves>Nature of Electromagnetic Waves

If the magnetic field of a plane electromagnetic wave is given by (The speed of light

= 3 \times 10^{8} m s^{- 1}

)

B = 100 \times 10^{- 6} \sin [2 π \times 2 \times 10^{15} (t - \frac{x}{c})]

then the maximum electric field associated with it is:

MEDIUM

Physics>Modern Physics>Electromagnetic Waves>Nature of Electromagnetic Waves

The energy associated with electric field is

(U_{E})

and with magnetic field is

(U_{B})

for an electromagnetic wave in free space. Then:

MEDIUM

Physics>Modern Physics>Electromagnetic Waves>Nature of Electromagnetic Waves

A radio transmitter sends out

60 W

of radiation. Assuming that the radiation is uniform on a sphere with the transmitter at its centre, the intensity

(i n W / m^{2})

of the wave at a distance

12 k m

MEDIUM

Physics>Modern Physics>Electromagnetic Waves>Nature of Electromagnetic Waves

What do you understand by the statement, “Electromagnetic waves transport momentum”?

MEDIUM

Physics>Modern Physics>Electromagnetic Waves>Nature of Electromagnetic Waves

For plane electromagnetic waves propagating in the

+ z

-direction, which one of the following combinations gives the correct possible direction for

\vec{E}

and

\vec{B}

field respectively?

MEDIUM

Physics>Modern Physics>Electromagnetic Waves>Nature of Electromagnetic Waves

The mean intensity of radiation on the surface of the Sun is about

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

The RMS value of the corresponding magnetic field is closest to:

EASY

Physics>Modern Physics>Electromagnetic Waves>Nature of Electromagnetic Waves

During the propagation of electromagnetic wave in a particular medium :-

EASY

Physics>Modern Physics>Electromagnetic Waves>Nature of Electromagnetic Waves

Write an expression for the speed of light in a material medium of relative permittivity

ε_{r}

and relative magnetic permeability

μ_{r}

EASY

Physics>Modern Physics>Electromagnetic Waves>Nature of Electromagnetic Waves

Electromagnetic waves can be deflected by

MEDIUM

Physics>Modern Physics>Electromagnetic Waves>Nature of Electromagnetic Waves

Magnetic field in a plane electromagnetic wave is given by,

\vec{B} = B_{0} \sin (k x + ω t) \hat{j} T

. Expression for corresponding electric field will be:

(Where

c

is speed of light)

EASY

Physics>Modern Physics>Electromagnetic Waves>Nature of Electromagnetic Waves

An electromagnetic wave is represented by the electric filed

\vec{E} = E_{0} \hat{n} \sin [ω t + (6 y - 8 z)] .

Taking unit vectors in

x, y

and

z

directions to be

\hat{i}, \hat{j}, \hat{k},

the directions of propagations

\hat{s},

is:

HARD

Physics>Modern Physics>Electromagnetic Waves>Nature of Electromagnetic Waves

The electric field component of a monochromatic radiation is given by

\vec{E} = 2 E_{0} \cos k z \cos ω t \hat{i}

, Its magnetic field

\vec{B}

is then given by:

MEDIUM

Physics>Modern Physics>Electromagnetic Waves>Nature of Electromagnetic Waves

An electromagnetic wave travelling in the

x -

direction has frequency of

2 \times 10^{14} H z

and electric field amplitude of

27 V m^{- 1}

oscillates in

Y -

direction. From the options given below, which one describes the magnetic field for this wave?

EASY

Physics>Modern Physics>Electromagnetic Waves>Nature of Electromagnetic Waves

In an electromagnetic wave in free space the root mean square value of the electric field is

E_{r m s} = 6 V m^{- 1}

. The peak value of the magnetic field is

MEDIUM

Physics>Modern Physics>Electromagnetic Waves>Nature of Electromagnetic Waves

The magnetic field of an electromagnetic wave is given by:

\vec{B} = 1.6 \times 10^{- 6} \cos (2 \times 10^{7} z + 6 \times 10^{15} t) (2 \hat{i} + \hat{j}) \frac{W b}{m^{2}}

The associated electric field will be:

EASY

Physics>Modern Physics>Electromagnetic Waves>Nature of Electromagnetic Waves

Consider an electromagnetic wave propagating in vacuum. Choose the correct statement:

HARD

Physics>Modern Physics>Electromagnetic Waves>Nature of Electromagnetic Waves

The electric field of a plane polarized electromagnetic wave in free space at time

t = 0

is given by the expression

\vec{E} (x, y) = 10 \hat{j} c o s (6 x + 8 z)

. The magnetic field

\vec{B} (x, z, t)

is given by (

c

is the velocity of light.)

EASY

Physics>Modern Physics>Electromagnetic Waves>Nature of Electromagnetic Waves

The electric field of a plane electromagnetic wave is given by

\vec{E} = E_{0} \hat{i} c o s (k z) c o s (ω t)

The corresponding magnetic field

\vec{B}

is then given by:

MEDIUM

Physics>Modern Physics>Electromagnetic Waves>Nature of Electromagnetic Waves

A red $L E D$ emits light at $0.1 watt$ uniformly around it. The amplitude of the electric field of the light at a distance of $1 m$ from the diode is:

The intensity of gamma radiation from a given source is I0. On passing through 37.5 mm of lead it is reduced to I08. The thickness of lead which will reduce it to I02 is

Important Questions on Electromagnetic Waves

Learn and Prepare for any exam you want !

The intensity of gamma radiation from a given source is $I_{0}$ . On passing through $37.5 mm$ of lead it is reduced to $\frac{I_{0}}{8}$ . The thickness of lead which will reduce it to $\frac{I_{0}}{2}$ is