Electromagnetic Waves
Practice Questions
MCQ (Single Correct Answer)
1

Column - I lists the waves of the electromagnetic spectrum. Column - II gives approximate frequency range of these waves. Match Column - I and Column - II and choose the correct match from the given choices.

Column I Column II
(A) Radiowaves (P) $$
10^{18} \text { to } 10^{20} \mathrm{~Hz}
$$
(B) Microwaves (P) $$
10^{11} \text { to } 5 \times 10^{14} \mathrm{~Hz}
$$
(C) Infrared (R) $$
10^4 \text { to } 10^8 \mathrm{~Hz}
$$
(D) X-rays (S) $$
10^9 \text { to } 10^{12} \mathrm{~Hz}
$$

COMEDK 2024 Evening Shift
2

An electromagnetic wave of frequency $$3 \mathrm{~MHz}$$ passes from vacuum into a dielectric medium $$(\mu_r=1)$$ of relative permittivity 4.0. Then,

COMEDK 2024 Afternoon Shift
3

The ratio of amplitude of magnetic field to the amplitude of electric field of an electromagnetic wave propagating in vacuum is

COMEDK 2023 Morning Shift
4

A plane electromagnetic wave of frequency $$20 \mathrm{~MHz}$$ travels through a space along $$x$$-direction. If the electric field vector at a certain point in space is $$6 \mathrm{~Vm}^{-1}$$, then what is the magnetic field vector at that point?

COMEDK 2023 Morning Shift
5

What feature of the infrared waves make it useful for the haze photography?

COMEDK 2023 Evening Shift
6

Speed of electromagnetic wave in a medium having relative permittivity $$\varepsilon_r$$ and relative permeability $$\mu_r$$ is (speed of light in air, $$c=3\times10^8$$ m/s)

COMEDK 2022
7

A 30 mW laser beam has a cross-sectional area of 15 mm2. The magnitude of the maximum electric field in this electromagnetic wave is given by

[Permuittivity of space, $$\varepsilon_0=9\times10^{-12}$$

Speed of light, $$c=3\times10^8$$ m/s]

COMEDK 2022
8

The correct arrangement in increasing order of wavelength of X-rays, UV rays, microwave is

COMEDK 2021
9

Which of the following waves are used to treatment of muscles ache?

COMEDK 2021
10

Which of the following has/have zero average value in a plane electromagnetic wave?

COMEDK 2020