Electromagnetic Waves
Practice Questions
MCQ (Single Correct Answer)
1

$$ \text { Match the following types of waves with their wavelength ranges } $$

$$ \begin{array}{|l|l|} \hline \text { Waves } & \text { Wavelength ranges } \\ \hline \text { i. Microwave } & \text { a. } 700 \mathrm{~nm} \text { to } 400 \mathrm{~nm} \\ \hline \text { ii. Visible light } & \text { b. } 1 \mathrm{~nm} \text { to } 10^{-3} \mathrm{~nm} \\ \hline \text { iii. Ultraviolet } & \text { c. } 0.1 \mathrm{~m} \text { to } 1 \mathrm{~mm} \\ \hline \text { iv. X-rays } & \text { d. } 400 \mathrm{~nm} \text { to } 1 \mathrm{~nm} \\ \hline \end{array} $$
KCET 2025
2

The total energy carried by the light wave when it travels from a rarer to a non-reflecting and nonabsorbing medium

KCET 2025
3

Electromagnetic waves are incident normally on a perfectly reflecting surface having surface area $A$. If $I$ is the intensity of the incident electromagnetic radiation and $c$ is the speed of light in vacuum, the force exerted by the electromagnetic wave on the reflecting surface is

KCET 2024
4

The ratio of the magnitudes of electric field to the magnetic field of an electromagnetic wave is of the order of

KCET 2023
5

Which of the following radiations of electromagnetic waves has the highest wavelength ?

KCET 2022
6

Suppose that the electric field amplitude of electromagnetic wave is $$E_0=120 \mathrm{~NC}^{-1}$$ and its frequency $$f=50 \mathrm{~MHz}$$. Then, which of the following value is incorrectly computed?

KCET 2021
7

The source of electromagnetic wave can be a charge

KCET 2021
8

A light beam of intensity $$20 \mathrm{~W} / \mathrm{cm}^2$$ is incident normally on a perfectly reflecting surface of sides $$25 \mathrm{~cm} \times 15 \mathrm{~cm}$$. The momentum imparted to the surface by the light per second is

KCET 2020
9

An antenna uses electromagnetic waves of frequency $$5 \mathrm{~MHz}$$. For proper working, the size of the antenna should be

KCET 2019
10

Due to Doppler's effect the shift in wavelength observed is $$0.1 \mathop A\limits^o$$ for a star producing wavelength $$6000 \mathop A\limits^o$$. Velocity of recession of the star will be

KCET 2019
11

An electromagnetic wave is travelling in $$x$$-direction with electric field vector given by, $$\mathbf{E}_y=E_0 \sin (k x-\omega t) \hat{\mathbf{j}}$$. The correct expression for magnetic field vector is

KCET 2019
12

The phenomenon involved in the reflection of radio-waves by ionosphere is similar to

KCET 2019
13
If $\mathbf{E}$ and $\mathbf{B}$ represent electric and magnetic field vectors of an electromagentic wave, the direction of propagation of the wave is along
KCET 2017