Magnetism: A Comprehensive Guide for Physics Year 12 Students

Question 1

Which of the following is NOT a fundamental property of magnetic fields?

Accepted Answer

Their shape is inherently circular.

Answer

They are vector fields, characterized by both magnitude and direction.

Answer

They have the ability to exert forces on moving electric charges.

Answer

They can be generated by either permanent magnets or moving electric charges.

Question 2

When a current-carrying wire is placed in a magnetic field, the direction of the resulting magnetic force is:

Accepted Answer

Perpendicular to both the current and the magnetic field.

Answer

Parallel to both the current and the magnetic field.

Answer

Aligned with the direction of the current.

Answer

Opposite to the direction of the current.

Question 3

The unit employed to quantify magnetic field strength is:

Accepted Answer

Tesla

Answer

Weber

Answer

Ampere

Answer

Gauss

Question 4

An electric motor operates by converting:

Accepted Answer

Electrical energy into kinetic energy.

Answer

Kinetic energy into electrical energy.

Answer

Magnetic energy into electrical energy.

Answer

Electrical energy into magnetic energy.

Question 5

Regarding the magnetic poles of a bar magnet, they are:

Accepted Answer

Situated at the extremities of the magnet.

Answer

Evenly distributed throughout the magnet.

Answer

Solely present at the center of the magnet.

Answer

Unfixed and capable of moving around the magnet.

Question 6

When a coil is rotated within a magnetic field, the induced emf within the coil is:

Accepted Answer

Directly proportional to the rate of change of magnetic flux.

Answer

Inversely proportional to the rate of change of magnetic flux.

Answer

Independent of the rate of change of magnetic flux.

Answer

Proportional to the strength of the magnetic field.

Question 7

The direction of the magnetic field created by a current-carrying wire is determined by:

Accepted Answer

The direction of the current

Answer

The length of the wire

Answer

The material of the wire

Answer

The temperature of the wire

Question 8

In a DC motor, the current in the armature is:

Accepted Answer

Direct

Answer

Alternating

Answer

Induced

Answer

Reversed

Question 9

The magnetic susceptibility of a material indicates its:

Accepted Answer

Ability to magnetize

Answer

Ability to conduct electricity

Answer

Ability to store energy

Answer

Ability to resist magnetization

Question 10

What is magnetic flux, and how does it relate to magnetic field strength and area?

Accepted Answer

Magnetic flux is the amount of magnetic field passing perpendicularly through a given area.

Answer

Magnetic flux is the density of magnetic dipoles in an area.

Answer

Magnetic flux is the energy stored in a magnetic field.

Answer

Magnetic flux is the force exerted by a magnetic field on a moving charge.

Question 11

Which property is characteristic of magnetic materials?

Accepted Answer

Ability to attract iron objects

Answer

Ability to conduct electricity efficiently

Answer

Ability to float on water

Answer

Ability to change color when exposed to light

Question 12

What is the orientation of the magnetic field surrounding a current-carrying wire?

Accepted Answer

Circular around the wire

Answer

Parallel to the wire's length

Answer

Perpendicular to the wire's length

Answer

Random and unpredictable

Question 13

Which of the following units is used to measure magnetic field strength in the SI system?

Accepted Answer

Tesla

Answer

Weber

Answer

Ampere

Answer

Volt

Question 14

What fundamental principle underlies the operation of an electric motor?

Accepted Answer

Conversion of electrical energy into mechanical energy

Answer

Conversion of mechanical energy into electrical energy

Answer

Generation of powerful magnetic fields

Answer

Amplification of sound waves

Question 15

Which material exhibits strong magnetic properties?

Accepted Answer

Iron

Answer

Plastic

Answer

Wood

Answer

Copper

Question 16

What is the quantitative relationship between magnetic field strength and magnetic flux density?

Accepted Answer

Directly proportional

Answer

Inversely proportional

Answer

Unrelated

Answer

Logarithmically proportional

Question 17

Which type of magnetic hysteresis is characterized by a material's resistance to magnetization?

Accepted Answer

Hard

Answer

Soft

Answer

Elastic

Answer

Plastic

Question 18

What is the primary function of slip rings in a DC motor?

Accepted Answer

To provide electrical connection between the armature and the external circuit

Answer

To reverse the direction of current flow in the armature

Answer

To generate a magnetic field

Answer

To reduce electrical resistance in the circuit

Question 19

What is the fundamental difference between paramagnetic and diamagnetic materials in terms of their magnetic behavior?

Accepted Answer

Paramagnetic materials are attracted to magnets, while diamagnetic materials are repelled.

Answer

Diamagnetic materials are attracted to magnets, while paramagnetic materials are repelled.

Answer

Both materials are attracted to magnets.

Answer

Both materials are repelled by magnets.

Question 20

Which of the following properties is NOT characteristic of magnetic materials?

Accepted Answer

Exhibit randomly oriented magnetic domains

Answer

Attracted to north and south poles of a magnet

Answer

Can retain their magnetism permanently

Answer

Can be induced to become magnetized

Question 21

What is the primary function of the commutator in a DC motor?

Accepted Answer

Reversing the direction of current flow

Answer

Maintaining a constant magnetic field

Answer

Reducing the voltage across the armature

Answer

Increasing the speed of the motor

Question 22

Which of the following is a known limitation of using a transformer?

Accepted Answer

Energy losses due to heat dissipation

Answer

Frequency conversion is not possible

Answer

Voltage regulation is unreliable

Answer

Only works with AC circuits

Question 23

What is the main purpose of utilizing a permanent magnet in a DC generator?

Accepted Answer

Providing a constant magnetic field

Answer

Generating an alternating current

Answer

Regulating the voltage output

Answer

Reducing the speed of rotation

Question 24

Which of the following is NOT a recognized type of magnetic field?

Accepted Answer

Elliptical

Answer

Uniform

Answer

Non-uniform

Answer

Radial

Question 25

What is the SI unit used to measure magnetic flux?

Accepted Answer

Weber (Wb)

Answer

Tesla (T)

Answer

Ampere (A)

Answer

Volt (V)

Question 26

What is the fundamental principle behind the operation of a moving-coil galvanometer?

Accepted Answer

Interaction between a current-carrying coil and an external magnetic field

Answer

Induction of an EMF in a coil moving within a magnetic field

Answer

Repulsion between two current-carrying coils

Answer

Attraction between a magnet and a piece of metal

Question 27

The magnetic field around a current-carrying wire is:

Accepted Answer

Circular around the wire

Answer

Parallel to the wire

Answer

Perpendicular to the wire

Answer

Elliptical around the wire

Question 28

Which factor does NOT influence the strength or direction of the magnetic field created by a current loop?

Accepted Answer

Temperature of the surrounding environment

Answer

Current flowing through the loop

Answer

Number of turns in the loop

Answer

Area of the loop

Question 29

Identify the material that is not magnetic:

Accepted Answer

Wood

Answer

Nickel

Answer

Cobalt

Answer

Iron

Question 30

In a DC motor, what is the purpose of the commutator?

Accepted Answer

To reverse the current direction in the coil, ensuring continuous rotation

Answer

To rotate the coil in the opposite direction

Answer

To decrease the coil's speed

Answer

To stop the coil's rotation

Question 31

Identify the characteristic that is NOT a property of magnetic fields:

Accepted Answer

Visibility

Answer

Production by moving charges

Answer

Exertion of force on moving charges

Answer

Ability to be shielded by certain materials

Question 32

Describe the direction of the magnetic force exerted on a moving charge:

Accepted Answer

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

Answer

Parallel to the charge's velocity

Answer

Parallel to the magnetic field

Question 33

Which of the following applications does not involve magnetism?

Accepted Answer

Microwave oven

Answer

MRI scanner

Answer

Compass

Answer

Electric guitar

Question 34

Which of the following best describes magnetic flux?

Accepted Answer

Amount of magnetic field passing perpendicularly through a given area

Answer

Strength of a magnetic field

Answer

Direction of a magnetic field

Question 35

A current-carrying wire experiences a force when placed in a uniform magnetic field. The direction of this force is:

Accepted Answer

Perpendicular to both the wire and the magnetic field

Answer

Along the direction of the current

Answer

Along the direction of the magnetic field

Question 36

Which of the following materials is classified as ferromagnetic?

Accepted Answer

Iron

Answer

Plastic

Answer

Aluminum

Answer

Copper

Question 37

The magnetic field around a current-carrying wire is:

Accepted Answer

Circular

Answer

Random

Answer

Straight

Answer

Elliptical

Question 38

The strength of the magnetic field inside a solenoid is:

Accepted Answer

Directly proportional to both the number of turns and the current

Answer

Inversely proportional to both the number of turns and the current

Answer

Independent of both the number of turns and the current

Question 39

In a generator, the primary purpose of the slip rings is to:

Accepted Answer

Connect the rotating coil to the external circuit

Answer

Store electrical energy

Answer

Increase the magnetic field strength

Answer

Reduce friction between the coil and the magnet

Question 40

The magnetic force between two current-carrying wires depends on the direction of the currents. If the currents are in the same direction, the force is:

Accepted Answer

Attractive

Answer

Repulsive

Question 41

What is the SI unit of magnetic flux density?

Accepted Answer

Tesla

Answer

Ampere-turn

Answer

Weber

Question 42

Which fundamental property distinguishes magnetic materials?

Accepted Answer

Their ability to attract or repel magnets

Answer

Their shiny appearance

Answer

Their ability to expand with heat

Answer

Their high electrical conductivity

Question 43

Describe the shape of the magnetic field generated by a current-carrying wire.

Accepted Answer

Circular, concentric with the wire

Answer

Radial, extending outward from the wire

Answer

Linear, running parallel to the wire

Answer

Tangential, running perpendicular to the wire

Question 44

Which material exhibits diamagnetic properties?

Accepted Answer

Copper

Answer

Iron

Answer

Nickel

Answer

Cobalt

Question 45

Identify the factor that primarily affects the strength of a magnetic field produced by a current-carrying wire.

Accepted Answer

Current strength

Answer

Thickness of the wire

Answer

Color of the wire

Answer

Length of the wire

Question 46

Distinguish between a solenoid and an electromagnet.

Accepted Answer

An electromagnet incorporates a ferromagnetic core, while a solenoid does not

Answer

Solenoids produce stronger magnetic fields

Answer

Solenoids are used in motors, while electromagnets are used in generators

Question 47

What is the standard unit for measuring magnetic field strength?

Accepted Answer

Tesla (T)

Answer

Ampere (A)

Answer

Weber (Wb)

Answer

Gauss (G)