Electromagnetism Fundamentals: Master the Basics of Electric and Magnetic Fields

Question 1

According to Gauss's law, what factor determines the net electric flux through any closed surface?

Accepted Answer

The charge enclosed by the surface

Answer

The area of the surface

Answer

The electric field strength

Answer

The permittivity of the medium

Question 2

Faraday's law of induction establishes a relationship between which physical quantities?

Accepted Answer

Magnetic flux and electromotive force

Answer

Electric potential and magnetic field

Answer

Current and magnetic field

Answer

Charge and magnetic flux

Question 3

Which quantity measures the resistance of a material to the flow of electric charge?

Accepted Answer

Resistivity

Answer

Conductivity

Answer

Permittivity

Answer

Susceptibility

Question 4

Ampere's law relates the circulation of the magnetic field around a closed loop to which factor?

Accepted Answer

The current flowing through the loop

Answer

The potential difference around the loop

Answer

The surface area enclosed by the loop

Answer

The charge enclosed by the loop

Question 5

Which of the following is a scalar quantity in electromagnetics?

Accepted Answer

Electric potential

Answer

Electric field

Answer

Magnetic induction

Answer

Current density

Question 6

The Biot-Savart law is applied to calculate the magnetic field at a point due to which source?

Accepted Answer

A current-carrying wire

Answer

A point charge

Answer

A solenoid

Answer

A capacitor

Question 7

Which material exhibits good electrical conductivity?

Accepted Answer

Copper

Answer

Rubber

Answer

Plastic

Answer

Wood

Question 8

Maxwell's equations are a set of four partial differential equations that describe the behavior of electric and magnetic fields. Which of the following is NOT one of Maxwell's equations?

Accepted Answer

Ohm's law

Answer

Gauss's law for magnetism

Answer

Gauss's law for electricity

Answer

Faraday's law of induction

Question 9

An electrically charged particle moving in a magnetic field experiences a force due to the interaction between the particle's charge and the magnetic field. What is the direction of this force?

Accepted Answer

Perpendicular to both the magnetic field and the particle's velocity

Answer

Parallel to the magnetic field

Answer

Antiparallel to the magnetic field

Answer

Parallel to both the magnetic field and the particle's velocity

Question 10

The electric field inside a conductor is:

Accepted Answer

Zero

Answer

Non-zero and uniform

Answer

Non-zero and non-uniform

Answer

Dependent on the shape of the conductor

Question 11

The magnetic field outside a long, straight wire carrying current is:

Accepted Answer

Uniform and perpendicular to the wire

Answer

Zero

Answer

Non-uniform and parallel to the wire

Answer

Non-uniform and perpendicular to the wire

Question 12

A transformer is an electrical device that transfers energy from one circuit to another through electromagnetic induction. What is the purpose of the core in a transformer?

Accepted Answer

To provide a low-reluctance path for magnetic flux

Answer

To insulate the windings from each other

Answer

To dissipate heat generated in the transformer

Answer

To store electrical energy

Question 13

Which statement is NOT true about electric fields?

Accepted Answer

They can be blocked by conducting materials.

Answer

They have both magnitude and direction.

Answer

They exert force on charged particles.

Question 14

Which Maxwell's equation describes the relationship between the change in magnetic field over time and the curl of the electric field?

Accepted Answer

Faraday's law of induction

Answer

Gauss's law

Answer

Ampere's circuital law with Maxwell's addition

Question 15

Which of the following is the SI unit of electric charge?

Accepted Answer

Coulomb

Answer

Ampere

Answer

Volt

Answer

Ohm

Question 16

Gauss's law relates electric field to:

Accepted Answer

Electric flux

Answer

Magnetic flux

Answer

Electric potential

Answer

Magnetic potential

Question 17

The curl of the electric field is related to:

Accepted Answer

Time-varying magnetic field

Answer

Time-invariant magnetic field

Answer

Time-varying electric field

Answer

Time-invariant electric field

Question 18

Ampere's law relates magnetic field to:

Accepted Answer

Electric current

Answer

Electric charge

Answer

Voltage

Answer

Resistance

Question 19

Which of Maxwell's equations describes the conservation of charge?

Accepted Answer

Gauss's law

Answer

Gauss's law for magnetism

Answer

Faraday's law

Answer

Ampere's law

Question 20

A uniform electric field is created between two parallel plates separated by a distance 'd'. If the potential difference between the plates is 'V', the electric field strength is:

Accepted Answer

V/d

Answer

2V/d

Answer

V/2d

Answer

0

Question 21

A current-carrying wire produces a magnetic field that is:

Accepted Answer

Circular

Answer

Linear

Answer

Elliptical

Answer

Parabolic

Question 22

The speed of an electromagnetic wave in a vacuum is given by:

Accepted Answer

c = √(μ₀/ε₀)

Answer

c = √(ε₀/μ₀)

Answer

c = (μ₀/ε₀)

Answer

c = (ε₀/μ₀)

Question 23

Which of the following is the SI unit for electric field intensity?

Accepted Answer

Tesla (T)

Answer

Gauss (G)

Answer

Coulomb (C)

Answer

Newton (N)

Question 24

According to Gauss's law, the net electric flux through any closed surface in a vacuum is directly proportional to the:

Accepted Answer

Total electric charge enclosed by the surface

Answer

Surface area of the Gaussian surface

Answer

Permittivity of the medium inside the surface

Answer

Volume of the Gaussian surface

Question 25

Faraday's law of induction states that the magnitude of the electromotive force (EMF) induced in a conductor is:

Accepted Answer

Equal to the rate of change of magnetic flux through the conductor

Answer

Proportional to the surface area of the conductor

Answer

Dependent on the resistance of the conductor

Answer

Independent of the direction of the magnetic field

Question 26

Ampere's law describes the relationship between the magnetic field and:

Accepted Answer

Moving electric charges and currents

Answer

Electric fields and voltages

Answer

Electromagnetic waves and energy

Answer

Magnetic materials and permeability

Question 27

The constitutive relationship that describes the relationship between electric field intensity (E) and electric displacement (D) in a material is:

Accepted Answer

D = εE

Answer

B = μH

Answer

J = σE

Answer

P = χE

Question 28

Which of the following is NOT a characteristic of electric fields?

Accepted Answer

Dependent on the presence of moving charges

Answer

Strength and direction

Answer

Ability to do work

Answer

Capable of storing energy

Question 29

Gauss's law for electrostatics relates the net electric flux (Φ) through a closed surface to the total electric charge (Q) enclosed within the surface. The relationship is expressed as:

Accepted Answer

Φ = Q/4πε₀

Answer

Φ = Q/ε₀

Answer

Φ = Qε₀

Answer

Φ is independent of Q

Question 30

According to Faraday's law of induction, the electromotive force (EMF) induced in a closed loop is equal to:

Accepted Answer

The negative rate of change of magnetic flux through the loop

Answer

The current flowing through the loop

Answer

The resistance of the loop

Answer

The potential difference across the loop

Question 31

Ampère's circuital law states that the line integral of the magnetic field strength around a closed path is:

Accepted Answer

Equal to the current enclosed by the path

Answer

Equal to the voltage drop around the path

Answer

Proportional to the resistance of the path

Answer

Independent of the current enclosed by the path

Question 32

Which of the following is NOT one of Maxwell's equations?

Accepted Answer

Lenz's law

Answer

Gauss's law for electric fields

Answer

Gauss's law for magnetic fields

Answer

Faraday's law of induction

Question 33

The SI unit of electric field strength is:

Accepted Answer

Volt per meter (V/m)

Answer

Coulomb per square meter (C/m²)

Answer

Tesla (T)

Answer

Weber (Wb)

Question 34

The SI unit of magnetic flux density is:

Accepted Answer

Tesla (T)

Answer

Weber per square meter (Wb/m²)

Answer

Ampere per meter (A/m)

Answer

Volt per meter (V/m)

Question 35

A straight current-carrying wire is placed in a uniform magnetic field. The magnetic force on the wire is:

Accepted Answer

Perpendicular to both the current and the magnetic field

Answer

Parallel to both the current and the magnetic field

Answer

Parallel to the current but perpendicular to the magnetic field

Answer

Perpendicular to the current but parallel to the magnetic field

Question 36

According to Gauss's law, the electric flux through a closed surface is proportional to the charge enclosed within the surface.

Accepted Answer

True

Answer

False

Question 37

Ampere's law relates the circulation of the magnetic field around a closed loop to the current flowing through the loop.

Accepted Answer

True

Answer

False

Question 38

Faraday's law of induction describes the relationship between a changing magnetic field and an induced voltage in a conductor.

Accepted Answer

True

Answer

False

Question 39

The permittivity of a material is a measure of its ability to store electric energy.

Accepted Answer

True

Answer

False

Question 40

The permeability of a material is a measure of its ability to store magnetic energy.

Accepted Answer

True

Answer

False

Question 41

An electric field is conservative if its line integral around any closed path is zero.

Accepted Answer

True

Answer

False

Question 42

A magnetic field is solenoidal if its divergence is zero.

Accepted Answer

True

Answer

False

Question 43

The Poynting vector represents the energy flow per unit area in an electromagnetic field.

Accepted Answer

True

Answer

False

Question 44

What is the direction of the electric field lines surrounding a positive charge?

Accepted Answer

Radially outward from the charge

Answer

Radially inward towards the charge

Answer

Circular, clockwise around the charge

Answer

Circular, counter-clockwise around the charge

Question 45

Which statement accurately describes Gauss's Law?

Accepted Answer

The total electric flux through any closed surface is directly proportional to the enclosed electric charge.

Answer

The electric field is always perpendicular to a conductor's surface.

Answer

The electric flux is always constant regardless of the enclosed charge.

Answer

The electric field inside a conductor is always zero.

Question 46

A loop of wire is placed within a changing magnetic field. What principle explains the induced electromotive force (EMF) in the loop?

Accepted Answer

Faraday's Law of electromagnetic induction

Answer

Maxwell's equations

Answer

Ampere's Law

Answer

Gauss's Law

Question 47

A parallel-plate capacitor is charged to a potential difference of 100 V. If the distance between the plates is doubled, how does the electric field between the plates change?

Accepted Answer

It is halved.

Answer

It is quadrupled.

Answer

It remains the same.

Answer

It is doubled.

Question 48

What creates a magnetic dipole moment?

Accepted Answer

A loop of current.

Answer

A uniform magnetic field.

Answer

A stationary point charge.

Answer

A uniform electric field.

Question 49

A charged particle moving within a magnetic field experiences a force perpendicular to both its velocity and the magnetic field. This force is called the:

Accepted Answer

Lorentz force

Answer

Gravitational force

Answer

Coulomb force

Answer

Electrostatic force

Question 50

What is the primary function of a transformer?

Accepted Answer

To change the voltage of an alternating current (AC) circuit.

Answer

To convert AC to DC.

Answer

To convert DC to AC.

Answer

To amplify the current in a circuit.