Magnetism and Electromagnetism MCQs Questions Answers [TOP 50]: Magnetism and electromagnetism are two related phenomena in physics that involve the behavior and interaction of electric charges and magnetic fields. Let’s explore each concept individually and then discuss their connection.
1. Magnetism: Magnetism refers to the property of certain materials to attract or repel each other. These materials are called magnets. Magnets have two poles, commonly referred to as the north pole (N) and the south pole (S). Like poles repel each other, while opposite poles attract.
Key points about magnetism:
a. Magnetic Field: A magnetic field is a region in space where the effects of magnetism are observed. It is represented by magnetic field lines that indicate the direction of the magnetic field. Magnetic field lines always form closed loops.
b. Magnetic Force: Magnets exert forces on each other due to their magnetic fields. The force between two magnets depends on their distance and the orientation of their poles. This force is strongest when the magnets are close together.
c. Magnetic Materials: Some materials, such as iron, nickel, and cobalt, can be easily magnetized. They are called ferromagnetic materials. Other materials, like copper and aluminum, are not easily magnetized and are called non-magnetic materials.
d. Earth’s Magnetic Field: The Earth itself acts as a giant magnet with its own magnetic field. The Earth’s magnetic field is crucial for navigation and is used by compasses to determine direction.
2. Electromagnetism: Electromagnetism describes the behavior of electric charges and their interaction with magnetic fields.
Key points about electromagnetism:
a. Electric Current: When electric charges move through a conductor, such as a wire, it creates an electric current. Electric currents generate magnetic fields around them. The direction of the magnetic field is determined by the direction of the current flow.
b. Electromagnetic Field: An electromagnetic field is a combination of an electric field and a magnetic field. Whenever there is an electric current, there is an associated magnetic field, and vice versa. Electromagnetic fields are produced by moving charges and changing magnetic fields.
c. Electromagnets: An electromagnet is a temporary magnet created by passing an electric current through a coil of wire. The magnetic field produced by the current can be controlled by adjusting the strength of the current. Electromagnets are widely used in various applications, such as electric motors, transformers, and MRI machines.
Connection between Magnetism and Electromagnetism: The connection between magnetism and electromagnetism lies in the fact that electric currents create magnetic fields. When an electric current flows through a wire, it produces a magnetic field around the wire. This phenomenon is the basis for electromagnetism. By controlling the electric current, you can control the strength and direction of the resulting magnetic field, allowing you to manipulate magnets and other magnetic materials.
Additionally, moving magnets or changing magnetic fields can induce electric currents in nearby conductors. This principle, known as electromagnetic induction, is the basis for technologies such as generators and transformers.
In summary, magnetism and electromagnetism are closely related concepts. Magnetism deals with the behavior of magnets and magnetic fields, while electromagnetism describes the interaction between electric currents and magnetic fields. The relationship between the two is fundamental to understanding various phenomena in physics and has numerous practical applications.
Magnetism and Electromagnetism MCQs NEET 2023
1. Which of the following materials is most commonly used to make permanent magnets?
a. Aluminum
b. Copper
c. Iron
d. Silver
Answer: c. Iron
2. What happens when like poles of two magnets are brought close together?
a. They attract each other.
b. They repel each other.
c. They merge into a single magnet.
d. They remain unaffected.
Answer: b. They repel each other.
3. Which of the following statements about magnetic fields is correct?
a. Magnetic field lines always diverge.
b. Magnetic field lines are always parallel to each other.
c. Magnetic field lines form closed loops.
d. Magnetic field lines extend indefinitely in space.
Answer: c. Magnetic field lines form closed loops.
4. What is the relationship between electric current and magnetic field?
a. Electric current is caused by magnetic fields.
b. Magnetic fields are caused by electric currents.
c. Electric current and magnetic field are unrelated.
d. Electric current and magnetic field are the same phenomenon.
Answer: b. Magnetic fields are caused by electric currents.
5. What happens when an electric current flows through a wire?
a. The wire becomes non-magnetic.
b. The wire becomes highly conductive.
c. The wire generates a magnetic field around it.
d. The wire becomes insulated.
Answer: c. The wire generates a magnetic field around it.
6. Which of the following devices uses the principle of electromagnetism?
a. Light bulb
b. Battery
c. Electric fan
d. Electric motor
Answer: d. Electric motor
7. What does an electromagnet consist of?
a. A permanent magnet
b. A coil of wire and an iron core
c. Two wires carrying electric current
d. A capacitor and a resistor
Answer: b. A coil of wire and an iron core
8. What is the phenomenon called when moving a magnet near a conductor induces an electric current in the conductor?
a. Electromagnetic induction
b. Magnetic resonance imaging
c. Electromagnetic radiation
d. Magnetic levitation
Answer: a. Electromagnetic induction
9. Which of the following is NOT a magnetic material?
a. Iron
b. Copper
c. Nickel
d. Cobalt
Answer: b. Copper
10. What is the SI unit of magnetic field strength?
a. Ampere
b. Ohm
c. Tesla
d. Volt
Answer: c. Tesla
Magnetism and Electromagnetism Quiz
11. Which of the following best describes a solenoid?
a. A permanent magnet
b. A coil of wire with a magnetic field
c. A non-magnetic material
d. A device that generates electric current
Answer: b. A coil of wire with a magnetic field
12. How does the strength of an electromagnet change if the current passing through the wire is increased?
a. The strength increases
b. The strength decreases
c. The strength remains constant
d. The strength becomes zero
Answer: a. The strength increases
13. Which law states that the magnetic field induced around a closed loop is directly proportional to the electric current passing through the loop?
a. Ampere’s law
b. Faraday’s law
c. Lenz’s law
d. Gauss’s law
Answer: a. Ampere’s law
14. Which of the following is an application of electromagnetic induction?
a. Electric guitar
b. Radio
c. Electric stove
d. All of the above
Answer: d. All of the above
15. Which of the following devices converts mechanical energy into electrical energy using electromagnetic induction?
a. Transformer
b. Generator
c. Inductor
d. Capacitor
Answer: b. Generator
16. What is the purpose of a commutator in a DC motor?
a. To reverse the direction of current flow
b. To convert AC to DC
c. To increase the speed of the motor
d. To decrease the voltage supplied to the motor
Answer: a. To reverse the direction of current flow
17. What happens to the direction of induced current in a wire if the magnetic field passing through the wire is reversed?
a. The current remains the same
b. The current decreases
c. The current increases
d. The current reverses direction
Answer: d. The current reverses direction
18. Which of the following materials is commonly used as a core material in electromagnets?
a. Aluminum
b. Rubber
c. Copper
d. Iron
Answer: d. Iron
19. What is the region of space around a magnet where its magnetic influence is felt called?
a. Magnetic field
b. Magnetic domain
c. Magnetic force
d. Magnetic flux
Answer: a. Magnetic field
20. Which of the following statements about magnetic poles is true?
a. Every magnet has a single pole.
b. Magnetic monopoles exist, but they are extremely rare.
c. Magnetic monopoles do not exist.
d. The strength of a magnetic pole is determined by its size.
Magnetism and Electromagnetism mcqs pdf
21. What is the property of a material that determines its ability to be magnetized called?
a. Magnetic field
b. Magnetic moment
c. Magnetic susceptibility
d. Magnetic permeability
Answer: d. Magnetic permeability
22. Which of the following devices uses the principle of electromagnetic induction to measure electrical current?
a. Voltmeter
b. Ammeter
c. Galvanometer
d. Multimeter
Answer: b. Ammeter
23. Which of the following statements about magnetic domains is true?
a. Magnetic domains are regions within a magnet where the magnetic field is weak.
b. Magnetic domains are aligned in random directions in a non-magnetized material.
c. Magnetic domains are independent of each other.
d. Magnetic domains cannot be changed by external magnetic fields.
Answer: b. Magnetic domains are aligned in random directions in a non-magnetized material.
24. What happens to the strength of the magnetic field when the distance from a magnet is increased?
a. The strength increases.
b. The strength decreases.
c. The strength remains the same.
d. It depends on the type of magnet.
Answer: b. The strength decreases.
25. Which of the following devices uses the principle of magnetic resonance to create detailed images of the human body?
a. MRI scanner
b. X-ray machine
c. Ultrasound machine
d. PET scanner
Answer: a. MRI scanner
26. What causes the needle of a compass to point north?
a. Earth’s gravitational pull
b. Earth’s electric field
c. Earth’s magnetic field
d. Earth’s atmospheric pressure
Answer: c. Earth’s magnetic field
27. Which of the following statements about electromagnetism is correct?
a. Electric charges are influenced only by magnetic fields.
b. Magnetic fields are created only by electric currents.
c. Electric currents are not affected by magnetic fields.
d. Electric currents and magnetic fields are interrelated.
Answer: d. Electric currents and magnetic fields are interrelated.
28. What is the phenomenon called when a material retains its magnetic properties even after the external magnetic field is removed?
a. Electromagnetic induction
b. Magnetic hysteresis
c. Magnetic resonance
d. Magnetic levitation
Answer: b. Magnetic hysteresis
29. Which of the following substances is NOT attracted to a magnet?
a. Iron
b. Nickel
c. Aluminum
d. Cobalt
Answer: c. Aluminum
30. The magnetic field of a permanent magnet is strongest:
a. At the poles
b. At the center
c. Along the sides
d. It is uniformly distributed
Answer: a. At the poles
Electromagnets Quiz Electricity Engineering MCQs
31. What happens to the magnetic field strength if the distance from a permanent magnet is doubled?
a. It becomes half as strong.
b. It becomes twice as strong.
c. It becomes four times as strong.
d. It remains the same.
Answer: a. It becomes half as strong.
32. Which of the following is a unit of magnetic flux density?
a. Tesla
b. Ampere
c. Joule
d. Watt
Answer: a. Tesla
33. The right-hand rule is commonly used to determine:
a. The direction of the magnetic field around a wire carrying current
b. The strength of a magnetic field
c. The polarity of a magnet
d. The resistance of a conductor
Answer: a. The direction of the magnetic field around a wire carrying current
34. What happens to the direction of an induced current if the magnetic field through a coil is reversed?
a. The direction of the induced current remains the same.
b. The induced current stops flowing.
c. The direction of the induced current is also reversed.
d. The magnitude of the induced current increases.
Answer: c. The direction of the induced current is also reversed.
35. Which law states that the electromotive force (EMF) induced in a circuit is directly proportional to the rate of change of magnetic flux through the circuit?
a. Ohm’s law
b. Ampere’s law
c. Faraday’s law
d. Lenz’s law
Answer: c. Faraday’s law
36. Which of the following is NOT an application of electromagnetic induction?
a. Electric transformers
b. Electric generators
c. Magnetic resonance imaging (MRI)
d. Cathode-ray tubes (CRTs)
Answer: d. Cathode-ray tubes (CRTs)
37. What is the purpose of a soft iron core in an electromagnet?
a. To increase the strength of the magnetic field
b. To decrease the resistance of the wire
c. To provide insulation for the wire
d. To protect the wire from overheating
Answer: a. To increase the strength of the magnetic field
38. What is the role of a diode in a circuit that uses an electromagnet?
a. To regulate the current flowing through the electromagnet
b. To increase the voltage supplied to the electromagnet
c. To reverse the direction of the current flowing through the electromagnet
d. To prevent the reverse flow of current through the electromagnet
Answer: d. To prevent the reverse flow of current through the electromagnet
39. Which of the following devices uses the principle of electromagnetic induction to convert mechanical energy into electrical energy?
a. Electric motor
b. Transformer
c. Generator
d. Capacitor
Answer: c. Generator
40. The strength of the magnetic field inside a solenoid can be increased by:
a. Increasing the number of turns in the solenoid
b. Decreasing the current flowing through the solenoid
c. Decreasing the length of the solenoid
d. Increasing the diameter of the solenoid
Answer: a. Increasing the number of turns in the solenoid
41. What is the role of a capacitor in a circuit that uses an electromagnet?
a. To store electrical energy
b. To convert AC to DC
c. To control the flow of current
d. To amplify the magnetic field
Answer: a. To store electrical energy
42. Which of the following statements about magnetic shielding is true?
a. Magnetic shielding can completely eliminate the effects of a magnetic field.
b. Magnetic shielding works only for static magnetic fields.
c. Magnetic shielding is achieved by using materials with high magnetic permeability.
d. Magnetic shielding is not possible due to the nature of magnetic fields.
Answer: c. Magnetic shielding is achieved by using materials with high magnetic permeability.
43. Which of the following materials is NOT commonly used as a permanent magnet?
a. Neodymium
b. Samarium cobalt
c. Ferrite
d. Aluminum
Answer: d. Aluminum
44. What is the primary source of Earth’s magnetic field?
a. The rotation of the Earth’s core
b. The movement of tectonic plates
c. The interaction of Earth’s atmosphere with the Sun
d. The magnetic properties of the Earth’s crust
Answer: a. The rotation of the Earth’s core
45. Which of the following phenomena explains the behavior of compass needles aligning with Earth’s magnetic field?
a. Electromagnetic induction
b. Magnetic hysteresis
c. Magnetic dipole moment
d. Magnetic resonance
Answer: c. Magnetic dipole moment
46. What causes a magnetic material to lose its magnetism when heated above a certain temperature, called the Curie temperature?
a. Alignment of magnetic domains
b. Randomization of magnetic domains
c. Increase in magnetic permeability
d. Loss of magnetic flux
Answer: b. Randomization of magnetic domains
47. What is the purpose of a Hall effect sensor?
a. To measure magnetic field strength
b. To generate electricity from magnetic fields
c. To shield against magnetic fields
d. To convert DC to AC
Answer: a. To measure magnetic field strength
48. Which of the following devices uses the principle of electromagnetic induction to convert electrical energy into mechanical energy?
a. Speaker
b. Microphone
c. Transformer
d. Electric motor
Answer: d. Electric motor
49. Which of the following materials is ferromagnetic?
a. Copper
b. Gold
c. Silver
d. Iron
Answer: d. Iron
50. What is the unit of magnetic flux?
a. Tesla
b. Weber
c. Ampere
d. Coulomb
Answer: b. Weber
51. In an electromagnet, the strength of the magnetic field can be increased by:
a. Decreasing the number of turns in the coil
b. Increasing the resistance of the wire
c. Decreasing the current flowing through the coil
d. Increasing the number of turns in the coil
Answer: d. Increasing the number of turns in the coil
52. Which of the following materials has the highest magnetic permeability?
a. Air
b. Water
c. Iron
d. Aluminum
Answer: c. Iron
53. What is the direction of the magnetic field around a current-carrying wire, according to the right-hand rule?
a. Away from the wire
b. Towards the wire
c. Circular around the wire
d. Parallel to the wire
Answer: c. Circular around the wire
54. What happens to the strength of the magnetic field if the current flowing through a wire is doubled?
a. It is halved
b. It remains the same
c. It is doubled
d. It depends on the resistance of the wire
Answer: c. It is doubled
55. Which law states that the induced electromotive force (EMF) in a circuit is equal to the rate of change of magnetic flux through the circuit?
a. Ohm’s law
b. Ampere’s law
c. Faraday’s law
d. Lenz’s law
Answer: c. Faraday’s law
56. Which of the following devices uses an electromagnet to convert electrical energy into mechanical energy?
a. Transformer
b. Generator
c. Inductor
d. Motor
Answer: d. Motor
57. What is the purpose of a commutator in a DC motor?
a. To control the speed of the motor
b. To reverse the direction of the current flow
c. To increase the voltage supplied to the motor
Answer: b. To reverse the direction of the current flow
58. Which of the following materials is used as a core in the construction of transformers?
a. Copper
b. Aluminum
c. Steel
d. Silicon
Answer: c. Steel
59. Which of the following materials exhibits the least magnetic behavior?
a. Diamagnetic
b. Ferromagnetic
c. Paramagnetic
d. Non-magnetic
Answer: a. Diamagnetic
60. What is the phenomenon called when a changing magnetic field induces an electric current in a nearby conductor?
a. Electromagnetic radiation
b. Electromagnetic interference
c. Electromagnetic induction
d. Electromagnetic resonance
Answer: c. Electromagnetic induction
61. Which of the following devices uses the principle of electromagnetic induction to store electrical energy?
a. Capacitor
b. Resistor
c. Inductor
d. Battery
Answer: a. Capacitor
62. What is the direction of the magnetic field inside a solenoid?
a. Along the length of the solenoid
b. Perpendicular to the solenoid
c. Radial from the center of the solenoid
d. Circular around the solenoid
Answer: a. Along the length of the solenoid
63. Which of the following statements about magnetic field lines is true?
a. Magnetic field lines only exist inside magnets.
b. Magnetic field lines are always straight and parallel.
c. Magnetic field lines do not intersect.
d. Magnetic field lines point from south to north.
Answer: c. Magnetic field lines do not intersect.
64. Which law states that the magnetic field around a closed loop is directly proportional to the electric current passing through the loop?
a. Ampere’s law
b. Gauss’s law
c. Ohm’s law
d. Coulomb’s law
Answer: a. Ampere’s law
65. Which of the following devices uses the principle of magnetic resonance to emit and detect radio waves?
a. MRI scanner
b. Radio transmitter
c. X-ray machine
d. Radar system
Answer: b. Radio transmitter
66. What is the phenomenon called when an external magnetic field causes a material to become magnetized?
a. Magnetic flux
b. Magnetic hysteresis
c. Magnetic saturation
d. Magnetic resonance
Answer: c. Magnetic saturation