Free Electromagnetic Induction MCQs with Answers
288 Electromagnetic Induction MCQs from Physics, each with the correct answer and a written explanation of why it is correct. Free and unlimited, with no account needed.
Changing magnetic flux induces an emf according to Faraday's law, while Lenz's law gives the direction that opposes the change producing it. Transformers apply induction between coils to step alternating voltage up or down, with turns ratio, current transformation and energy losses determining practical operation.
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Read the Electromagnetic Induction notesFree MDCAT chapter notes with key terms288 questions · page 5 of 15
- A. Transformer
- B. D.C. dynamo
- C. A.C. generator
- D. None of these
Explanation: The practical illustration of mutual induction is seen in a transformer.
Correct answer: Transformer- A. I ohm x 1 sec
- B. 1 ohm x l hertz
- C. 1 ohm x 1 metre
- D. All of above
Explanation: One henry (H) is equal to 1 ohm x 1 second.The unit of inductance, the henry, is defined as the amount of inductance in a circuit in which…
Correct answer: I ohm x 1 sec- A. Charge at rest
- B. Charge in motion
- C. Positive charge at rest
- D. None of them
Explanation: A magnetic compass will be deflected if it is kept near a charge in motion.
Correct answer: Charge in motion- A. Self induction
- B. Mutual induction
- C. Inductance
- D. Both (a) and (b)
Explanation: The phenomenon of producing an electromotive force (emf) in a coil due to the current change is called self-induction.
Correct answer: Self induction- A. Ampere
- B. Coulomb
- C. Farad
- D. Henry
Explanation: The SI unit of self-inductance is Henry. It represents the amount of inductance that will produce a voltage of 1 volt across its terminals…
Correct answer: Henry- A. Option A
- B. Option B
- C. Option C
- D. Option D
Explanation: Self-induction is expressed as: ε = -L di/dtThis equation tells us:ε (varepsilon): Represents the induced emf (electromotive force) in…
Correct answer: Option B- A. Area of the coil
- B. Number of turns
- C. Distance between the coil
- D. All of the above
Explanation: The mutual induction between two coils depends upon all of the above factors:Area of coil: The mutual induction is influenced by the area…
Correct answer: All of the above- A. Core material
- B. Weight of coil
- C. Number of turns of the coil
- D. Area of coil
Explanation: The self-inductance of a coil does not depend upon the weight of the coil.Self-inductance is primarily determined by the physical…
Correct answer: Weight of coil- A. Option A
- B. Option B
- C. Option C
- D. Option D
Explanation: The energy stored in a magnetic field can be calculated using the formula: E=1/2 LI2Where:U is the energy stored in the magnetic field (in…
Correct answer: Option A- A. Option A
- B. Option B
- C. Option C
- D. Option D
Explanation: The two equations that can potentially represent the self-inductance of a long solenoid are:(b) L = μ₀NI²A(c) L = μ₀n²AlHowever, it's…
Correct answer: Option C- A. Mutual induction
- B. Self induction
- C. Self inductance
- D. Mutual inductance
Explanation: The ratio of the self-induced electromotive force (emf) to the rate of change of current in the coil is known as self-inductance.
Correct answer: Self inductance- A. Mutual induction
- B. Self induction
- C. Mutual inductance
- D. Both (a) and (c)
Explanation: The correct answer is Both (a) and (c).There are two key concepts at play here:Mutual induction: This refers to the phenomenon where a…
Correct answer: Both (a) and (c)- A. Remains constant
- B. Decrease
- C. Increase
- D. Becomes zero
Explanation: When a coil is wound on an iron core, the flux through it will increase.The presence of an iron core in a coil increases the magnetic…
Correct answer: Increase- A. E = 005 J
- B. E = 10J
- C. E = 0.1 J
- D. E = 50 J
Explanation: To calculate the energy stored in the magnetic field of the coil, we can use the formula: E=1/2 LI2where:E is the energy stored in the…
Correct answer: E = 0.1 J- A. Magnetic field
- B. Length
- C. Material of the conductor
- D. All of the above
Explanation: The motional electromotive force (emf) produced in a conductor depends upon all of the above factors:Magnetic field: The strength of the…
Correct answer: All of the above- A. Electrical energy into mechanical energy
- B. Mechanical energy into electrical energy
- C. Chemical energy into mechanical energy
- D. Heat energy into electrical energy
Explanation: An AC generator is a device that converts mechanical energy into electrical energy.AC generators, also known as alternators, operate based…
Correct answer: Mechanical energy into electrical energy- A. Option A
- B. Option B
- C. Option C
- D. Option D
Explanation: The equation for the magnitude of the emf induced in the coil of an AC generator is:ε = NBAωsinθWhere:ε (varepsilon): Represents the…
Correct answer: Option A- A. A.C generator
- B. Motor
- C. Converter
- D. Vibrator
Explanation: A device that converts mechanical energy into electrical energy is called an A.C.
Correct answer: A.C generator- A. Option A
- B. Option B
- C. Option C
- D. Option D
Explanation: The correct formula for the energy stored per unit volume inside a solenoid is: u=1/2 u0B2Where:u is the energy stored per unit volume (in…
Correct answer: Option B- A. Dynamo
- B. Rectifier
- C. Motor
- D. Transformer
Explanation: An alternating current (AC) is converted into direct current (DC) by a device called a Rectifier.A rectifier is an electrical device that…
Correct answer: Rectifier