Electromagnetic Waves Questions! Trivia Quiz

14 Questions | Total Attempts: 467  Settings  • 1.
The electric field intensity produced by the radiations coming from 100 W bulb at a 3 m distance is E. the electric field intensity produced by the radiations coming from 50 W bulb at the same distance is
• A.
• B.
• C.
• D.
• 2.
One requires 11eV of energy to dissociate a carbon monoxide molecule into carbon and oxygen atoms. The minimum frequency of the appropriate electromagnetic radiation to achieve the dissociation lies in
• A.

Visible region

• B.

Infrared region

• C.

Ultraviolet region

• D.

Microwave region

• 3.
The electric and magnetic field of an electromagnetic wave are
• A.

In opposite phase and perpendicular to each other

• B.

In opposite phase and parallel to each other

• C.

In phase and perpendicular to each other

• D.

In phase and parallel to each other

• 4.
The velocity of electromagnetic radiation in a medium of permittivity ∈0 and permeability μ0 is given by
• A.
• B.
• C.
• D.
• 5.
The electric and the magnetic field, associated with an e.m. wave, propagating along the +z-axis, can be represented by
• A.
• B.
• C.
• D.
• 6.
If μ0 be the permeability and k0, the dielectric constant of a medium, its refractive index is given by
• A.
• B.
• C.
• D.
• 7.
The amplitude of an electromagnetic wave in the vacuum is doubled with no other changes made to the wave. As a result of this doubling of the amplitude, which of the following statement is correct?
• A.

The speed of wave propagation changes only

• B.

The frequency of the wave changes only

• C.

The wavelength of the wave changes only

• D.

None of the above is true

• 8.
If a 100-watt bulb acts as a point source and has 2.5% efficiency, the intensity of this bulb at 3 m is
• A.

0.022 Wm-2

• B.

0.22 Wm-2

• C.

4.4 Wm-2

• D.

0.033 Wm-2

• 9.
A plane electromagnetic wave is an incident on a material surface. The wave delivers momentum p and energy E. Then
• A.

P ≠ 0, E ≠ 0

• B.

P = 0, E = 0

• C.

P = 0, E ≠ 0

• D.

P ≠ 0, E = 0

• 10.
When a plane electromagnetic wave travels in a vacuum, the average electric energy density is given by (here Eo is the amplitude of the electric field of the wave)
• A.
• B.
• C.
• D.
• 11.
The frequencies of X-rays, γ-rays and ultraviolet rays are respectively a, b and c. Then
• A.

A < b, b > c

• B.

A > b, b > c

• C.

A > b, b < c

• D.

A < b, b < c

• 12.
Poynting vector gives
• A.

The magnetic field at a point due to a current in a straight conductor

• B.

The electric field at a point between the plates of a parallel plate capacitor

• C.

The rate of flow of energy perpendicular to direction of motion through unit area in an electromagnetic field

• D.

Total energy of electromagnetic wave

• 13.
The frequency of e.m. wave which is best suited to observe a particle of radius 3 × 10-1 cm is of the order of
• A.

1015 Hz

• B.

1014 Hz

• C.

1013 Hz

• D.

1012 Hz

• 14.
The magnetic field in a plane electromagnetic wave is given by By = 2 × 10-7 sin (0.5 × 103 x + 1.5 × 1011 t). This electromagnetic wave is
• A.

A visible light

• B.

An infrared wave

• C.

A microwave

• D. Back to top