# Electromagnetic Induction mcq

### Electromagnetic Induction mcq

Electromagnetic induction is the production of an electromotive force ( EMF) in a conductor due to :
a) The flow of electric current
b) The presence of a magnetic field
c) Both electric current and magnetic field
d) None of the above

Answer: b) The presence of a magnetic field

Who is credited with the discovery of electromagnetic induction?
b) Thomas Edison
c) Albert Einstein
d) Nikola Tesla

According to Faraday’s law of electromagnetic induction, the magnitude of the induced EMF is directly proportional to:
a) The rate of change of electric current
b) The rate of change of magnetic field
c) The resistance of the conductor
d) The length of the conductor

Answer: b) The rate of change of magnetic field

Faraday’s law of electromagnetic induction is a consequence of:
a) Ampere’s law
b) Ohm’s law
c) Gauss’s law
d) Maxwell’s equations

Which of the following, factors does not affect the magnitude of the induced EMF ?
a) The strength of the magnetic field
b) The velocity of the conductor
c) The length of the conductor
d) The resistance of the conductor

Answer: d) The resistance of the conductor

Lenz’s law is related to the direction of the induced current and states that the induced current will flow in a direction that:
a) Opposes the change in the magnetic field
b) Enhances the change in the magnetic field
c) Follows the direction of the magnetic field
d) Is independent of the magnetic field

Answer: a) Opposes the change in the magnetic field

An electromagnetic induction experiment can be conducted by moving a magnet:
a) Towards a stationary conductor
b) Away from a stationary conductor
c) Parallel to a stationary conductor
d) All of the above

Answer: d) All of the above

The unit of magnetic flux is:
a) Tesla (T)
b) Henry (H)
c) Weber (Wb)
d) Ampere (A)

a) Cancel out the magnetic field
b) Increase the magnetic field
c) Oppose the change in the magnetic field
d) Enhance the change in the magnetic field

Answer: c) Oppose the change in the magnetic field

An increase in the number of turns in a coil will result in:
a) An increase in the magnetic field strength
b) A decrease in the magnetic field strength
c) No change in the magnetic field strength
d ) A change in the direction of the magnetic field

Answer : a) An increase in the magnetic field strength

A device that uses electromagnetic induction to convert mechanical energy into electrical energy is called:
a) Transformer
b) Motor
c) Generator
d) Inductor

Transformers are based on the principle of:
a) Mutual inductance
b) Self-inductance
c) Capacitance
d) Resistance

In a step up transformer , the number of turns in the secondary coil is :
a) Equal to the number of turns in the primary coil
b) Less than the number of turns in the primary coil
c) Greater than the number of turns in the primary coil
d) Unrelated to the number of turns in the primary coil

Answer: c) Greater than the number of turns in the primary coil

Which of the following is not a component of a transformer ?
a) Core
b) Primary coil
c) Secondary coil
d) Switch

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

Answer: b) Output power to input power

Eddy currents are:
a) Longitudinal currents induced in a conductor
b) DC currents generated by electromagnetic induction
c) Circular currents induced in a conductor
d) Static currents present in a conductor

Answer: c) Circular currents induced in a conductor

Eddy currents in a conductor can be reduced by:
a) Increasing the magnetic field strength
b) Decreasing the resistance of the conductor
c) Using a laminated or segmented core
d) Increasing the number of turns in the coil

Answer: c) Using a laminated or segmented core

The phenomenon of self-induction occurs when:
a) A changing current in a coil induces an EMF in another nearby coil
b) A changing magnetic field induces an EMF in the same coil
c) A varying resistance in a circuit induces an EMF in a coil
d) A varying capacitance in a circuit induces an EMF in a coil

Answer: b) A changing magnetic field induces an EMF in the same coil

The SI unit of inductance is:
a) Ohm (Ω)
b) Volt (V)
d) Henry (H)

Inductors are commonly used in electrical circuits to:
a) Store electrical energy in a magnetic field
b) Convert electrical energy into mechanical energy
c) Increase the voltage of an AC signal
d) Decrease the resistance of a circuit

Answer: a) Store electrical energy in a magnetic field

The time constant of an RL circuit is given by the product of the resistance (R) and the:
a) Capacitance (C)
b) Inductance (L)
c) Voltage (V)
d) Current (I)

The reactance of an inductor is proportional to:
a) The frequency of the AC signal
b) The resistance of the circuit
c) The capacitance of the circuit
d) The voltage across the inductor

Answer: a) The frequency of the AC signal

The phenomenon of electromagnetic induction is the basis for the operation of:
a) Electric motors
b) Transformers
c) Generators
d) All of the above

Answer: d) All of the above

Which of the following is an example of electromagnetic induction?
a) The heating effect of an electric current
b) The production of light in an incandescent bulb
c) The operation of a loudspeaker
d) The generation of electricity in a hydroelectric power plant

Answer: d) The generation of electricity in a hydroelectric power plant

The principle of electromagnetic induction is used in:
a) Magnetic resonance imaging (MRI)
b) Wireless charging of electronic devices
c) Inductive proximity sensors
d) All of the above

Answer: d) All of the above

A magnetic field is produced around a current-carrying conductor due to:
a) Electromagnetic induction
b) Electric resistance
c) Joule heating
d) Magnetic hysteresis

Which of the following devices does not use electromagnetic induction?
a) Electric guitar pickup
b) Electric power steering
c) Solar panel
d) Vacuum cleaner

The direction of the induced current in a loop of wire can be determined using:
a) Lenz’s law
b) Ohm’s law
c) Kirchhoff’s laws
d) Gauss’s law

A generator converts:
a) Electrical energy into mechanical energy
b) Mechanical energy into electrical energy
c) Heat energy into electrical energy
d) Electrical energy into heat energy

Answer: b) Mechanical energy into electrical energy

The phenomenon of electromagnetic induction is governed by the laws of:
a) Newtonian mechanics
b) Quantum mechanics
c) Classical electromagnetism
d) Thermodynamics