# Electromagnetic Induction MCQs with Answers

Electromagnetic Induction MCQs are very important test and often asked by various testing services and competitive exams around the world. Here you will find all the Important Electromagnetic Induction MCQs for Preparation.

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## Electromagnetic Induction Online MCQs with Answers

Electromagnetic induction is the process of generating:
a) Electric charge due to magnetic field
b) Magnetic field due to electric charge
c) Electric current due to magnetic field
d) Magnetic field due to electric current

c) Electric current due to magnetic field

According to Faraday’s law of electromagnetic induction, the induced electromotive force (emf) is proportional to:
a) The strength of the magnetic field
b) The velocity of the conductor
c) The area of the conductor
d) The rate of change of magnetic flux

d) The rate of change of magnetic flux

Lenz’s law states that the direction of the induced current in a conductor is such that it:
a) Opposes the motion of the conductor
b) Supports the motion of the conductor
c) Depends on the resistance of the conductor
d) Depends on the voltage applied to the conductor

a) Opposes the motion of the conductor

The phenomenon of self-induction occurs when:
a) A changing current in one coil induces a current in another coil
b) A changing magnetic field induces a current in the same coil
c) A magnetic field is produced due to the flow of current in a coil
d) A changing magnetic field induces a voltage in a nearby coil

b) A changing magnetic field induces a current in the same coil

The unit of magnetic flux is:
a) Tesla
b) Weber
c) Henry
d) Volt

b) Weber

A transformer works based on the principle of:
a) Electromagnetic induction
b) Electrostatic induction
c) Magnetic permeability
d) Magnetic hysteresis

a) Electromagnetic induction

The primary coil of a transformer is connected to a 120V AC power supply and has 1000 turns. If the secondary coil has 2000 turns, what is the voltage across the secondary coil?
a) 120V
b) 240V
c) 60V
d) 480V

b) 240V

The primary coil of a transformer has 500 turns and is connected to a 240V AC power supply. If the secondary coil has 1000 turns, what is the voltage across the secondary coil?
a) 120V
b) 240V
c) 480V
d) 960V

c) 480V

The step-up transformer is used to:
a) Increase the voltage and decrease the current
b) Decrease the voltage and increase the current
c) Increase the voltage and increase the current
d) Decrease the voltage and decrease the current

a) Increase the voltage and decrease the current

The step-down transformer is used to:
a) Increase the voltage and decrease the current
b) Decrease the voltage and increase the current
c) Increase the voltage and increase the current
d) Decrease the voltage and decrease the current

b) Decrease the voltage and increase the current

In a transformer, if the primary coil has more turns than the secondary coil, the transformer is called:
a) Step-up transformer
b) Step-down transformer
c) Isolation transformer
d) Auto transformer

b) Step-down transformer

In a transformer, if the secondary coil has more turns than the primary coil, the transformer is called:
a) Step-up transformer
b) Step-down transformer
c) Isolation transformer
d) Auto transformer

a) Step-up transformer

The efficiency of a transformer is given by the ratio of:
a) Output power to input power
b) Input power to output power
c) Voltage across the primary coil to voltage across the secondary coil
d) Current through the primary coil to current through the secondary coil

a) Output power to input power

The magnetic field inside a solenoid can be increased by:
a) Increasing the current flowing through the solenoid
b) Increasing the number of turns in the solenoid
c) Decreasing the length of the solenoid
d) Increasing the resistance of the solenoid

b) Increasing the number of turns in the solenoid

A coil is placed in a magnetic field. If the number of turns in the coil is doubled, the induced emf will:
a) Double
b) Halve
c) Remain the same
d) Increase by a factor of four

a) Double

The phenomenon of electromagnetic induction is used in:
a) Electric motors
b) Generators
c) Transformers
d) All of the above

d) All of the above

An AC generator converts:
a) Mechanical energy into electrical energy
b) Electrical energy into mechanical energy
c) Heat energy into electrical energy
d) Sound energy into electrical energy

a) Mechanical energy into electrical energy

In an AC generator, the frequency of the generated alternating current depends on:
a) The speed of rotation of the coil
b) The strength of the magnetic field
c) The number of turns in the coil
d) All of the above

a) The speed of rotation of the coil

The direction of the induced current in an AC generator changes:
a) Every half-cycle
b) Every quarter-cycle
c) Every full cycle
d) It does not change

b) Every quarter-cycle

A coil is rotated in a magnetic field. The magnitude of the induced emf can be increased by:
a) Increasing the speed of rotation
b) Increasing the number of turns in the coil
c) Increasing the strength of the magnetic field
d) All of the above

d) All of the above

An electric motor converts:
a) Electrical energy into mechanical energy
b) Mechanical energy into electrical energy
c) Heat energy into electrical energy
d) Sound energy into electrical energy

a) Electrical energy into mechanical energy

The direction of the force experienced by a current-carrying conductor placed in a magnetic field can be determined using:
a) Fleming’s left-hand rule
b) Fleming’s right-hand rule
c) Lenz’s law

b) Fleming’s right-hand rule

The speed of an electric motor can be increased by:
a) Increasing the current flowing through the motor
b) Increasing the voltage applied to the motor
c) Increasing the number of turns in the motor coil
d) All of the above

c) Increasing the number of turns in the motor coil

A generator and a motor are essentially the same device, but their operation is:
a) Inverse to each other
b) Independent of each other
c) Identical to each other
d) Unrelated to each other

a) Inverse to each other

The phenomenon of electromagnetic induction is based on the law of conservation of:
a) Energy
b) Charge
c) Momentum
d) Mass

a) Energy

A coil of wire is connected to a galvanometer. If a magnet is moved towards the coil, the galvanometer will show:
a) A momentary deflection in one direction
b) A momentary deflection in the opposite direction
c) No deflection
d) A continuous deflection

a) A momentary deflection in one direction

A coil of wire is connected to a galvanometer. If a magnet is moved away from the coil, the galvanometer will show:
a) A momentary deflection in one direction
b) A momentary deflection in the opposite direction
c) No deflection
d) A continuous deflection

b) A momentary deflection in the opposite direction

The strength of the induced emf can be increased by:
a) Increasing the speed of the magnet
b) Increasing the number of turns in the coil
c) Increasing the strength of the magnet
d) All of the above

d) All of the above

The phenomenon of electromagnetic induction is used in the functioning of:
a) Electric power plants
b) Electric generators
c) Electric transformers
d) All of the above

d) All of the above

A transformer has 500 turns in the primary coil and 1000 turns in the secondary coil. If the voltage across the primary coil is 100V, what is the voltage across the secondary coil?
a) 50V
b) 100V
c) 200V
d) 400V

c) 200V

A transformer has 200 turns in the primary coil and 400 turns in the secondary coil. If the voltage across the primary coil is 120V, what is the voltage across the secondary coil?
a) 30V
b) 60V
c) 120V
d) 240V

d) 240V

A coil of wire is placed in a changing magnetic field. The induced current in the coil can be increased by:
a) Increasing the resistance of the coil
b) Increasing the number of turns in the coil
c) Increasing the velocity of the coil
d) All of the above

b) Increasing the number of turns in the coil

The concept of mutual induction is based on the principle of:
b) Lenz’s law
c) Coulomb’s law
d) Ohm’s law

The direction of the induced current in a coil can be determined using:
a) Lenz’s law
b) Coulomb’s law
c) Ampere’s law
d) Ohm’s law

a) Lenz’s law

A changing magnetic field can induce an emf in a conductor by:
a) Moving the conductor in the magnetic field
b) Moving the magnetic field around the conductor
c) Changing the intensity of the magnetic field
d) All of the above

d) All of the above

The direction of the induced current in a coil can be reversed by:
a) Reversing the magnetic field
b) Reversing the direction of motion of the coil
c) Increasing the resistance of the coil
d) Increasing the number of turns in the coil

a) Reversing the magnetic field

The strength of the induced emf can be increased by:
a) Increasing the speed of the motion
b) Increasing the strength of the magnetic field
c) Increasing the number of turns in the coil
d) All of the above

d) All of the above

A transformer has an efficiency of 90%. If the input power is 100W, what is the output power?
a) 10W
b) 90W
c) 100W
d) 110W

b) 90W

A transformer has an efficiency of 80%. If the input power is 200W, what is the output power?
a) 40W
b) 160W
c) 200W
d) 250W