Electromagnetic Fields and Waves MCQs (Part-4)

What defines the electric field intensity in an electromagnetic wave?

A Electric current
B Force per unit charge
C Charge
D Voltage

The magnetic field intensity is proportional to which of the following?

A Resistance
B Electric field
C Voltage
D Electric current

Which of Maxwell’s equations describes the relationship between the electric field and charge distribution?

A Lenz’s Law
B Gauss’s Law
C Faraday’s Law
D Ampere’s Law

What type of electromagnetic waves is used for communication via cell phones?

A X-rays
B Infrared waves
C Microwaves
D Radio waves

Which principle explains the induction of an electric current by a changing magnetic field?

A Lenz’s law
B Faraday’s law
C Ampere’s law
D Gauss’s law

What is the unit of magnetic flux?

A Weber
B Volt
C Ampere
D Tesla

What does Gauss’s Law state about the electric flux?

A It varies with distance
B It is constant
C It depends on the magnetic field
D It is proportional to enclosed charge

In an electromagnetic wave, which of the following is true about the electric and magnetic fields?

A They are independent
B They are perpendicular
C They are parallel
D They are in the same direction

What effect does a dielectric material have in a capacitor?

A Increases resistance
B Decreases resistance
C Decreases capacitance
D Increases capacitance

What happens when an electromagnetic wave enters a medium with a higher refractive index?

A Wavelength increases
B Speed increases
C Wave bends toward normal
D Wave bends away from normal

Which of these materials are best for blocking electromagnetic interference (EMI)?

A Insulators
B Magnetic materials
C Dielectrics
D Conductors

What is the purpose of the displacement current in Maxwell’s equations?

A To account for changing electric fields
B To reflect waves
C To generate magnetic fields
D To induce electric current

What is the characteristic of a perfect electric conductor in terms of electromagnetic waves?

A Polarizes waves
B Absorbs all waves
C Transmits all waves
D Reflects all waves

The term “electromagnetic spectrum” refers to:

A Heat radiation
B Sound wave frequencies
C Range of electromagnetic waves
D All visible light

Which of the following describes the propagation of electromagnetic waves?

A Through a vacuum
B Only through gases
C Only through liquids
D Only through solids