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 12 of 15
- A. Definitely true
- B. Probably true
- C. Data inadequate
- D. Probably false
- E. Definitely false
Explanation: Step 1: Key facts from the passageThe State cultivates 3.2 lakh tons of mangoes.The mangoes are of premium quality.Mangoes are the second…
Correct answer: Data inadequate- A. 20
- B. 18
- C. 24
- D. 26
- E. None of these
Explanation: The triangles are AFG, GHB, HED, EFC, MFG, MGH, MHE, MEF, FJM, MJG, MGK, KMH, HLM, MLE, MEI, IMF, FHE, FHG, GEF, GEH.
Correct answer: 20- A. A. If statement I is the cause and statement II is its effect;
- B. B. If statement II is the cause and statement I is its effect;
- C. C. If both the statements I and II are independent causes;
- D. D. If both the statements I and II are effects of independent causes:
- E. E. If both the statements I and II are effects of some common cause;
Explanation: The correct answer is Option A. Babar's abnormal behavior (Statement I) is likely the reason his father decided to take him to a doctor…
Correct answer: A. If statement I is the cause and statement II is its effect;- A. 9
- B. 18
- C. 20
- D. 15
Explanation: This is the correct count of educated people who are employed, derived from adding the two relevant segments in the diagram: 3 and 6.
Correct answer: 9- A. Increase
- B. Decrease
- C. Becomes Zero
- D. Remains constant
Explanation: When a motor is overloaded, its speed decreases due to the increased load.
Correct answer: Decrease- A. 2.5 V
- B. 0.4 V
- C. 10 V
- D. -10 V
Explanation: To find the induced electromotive force (e.m.f) in a coil when the current is changing, you can use the formula: ε=−L ΔI/Δt Given that the…
Correct answer: -10 V- A. 1 V
- B. 1.5 V
- C. 0.1 V
- D. 0.15 V
Explanation: We can use Faraday's law of induction; emf=−N(ΔΦ/Δt )The change in magnetic flux (ΔΦ) is:ΔΦ=Φfinal −Φinitia = (2×10−4 Wb)−(6×10−4 Wb) =…
Correct answer: 1 V- A. Zero
- B. Maximum
- C. ϵ = L(∆ I/ ∆t)
- D. ϵ =- L(∆ I/ ∆t)
Explanation: The magnitude of self-induced electromotive force (emf) in a coil, also known as back emf, is given by Faraday's law of electromagnetic…
Correct answer: Zero- A. It does not have any effect.
- B. It reverses the direction of current.
- C. It increases the current in the motor.
- D. It decreases the current in the motor.
Explanation: Because the back e.m.f. acts in opposition to the supply voltage, the net voltage across the motor's windings is the difference between…
Correct answer: It decreases the current in the motor.- A. cuts the magnetic flux.
- B. follows the path of magnetic flux.
- C. moves parallel to the magnetic field.
- D. moves perpendicular to the magnetic field.
Explanation: Faraday's law of electromagnetic induction states that an electromotive force (e.m.f.) is induced in a conductor when there is a change in…
Correct answer: cuts the magnetic flux.- A. low resistivity.
- B. decrease the area.
- C. strong magnetic field.
- D. increase the thickness.
Explanation: Eddy currents result in power loss in conducting materials due to the resistance encountered by the circulating currents.
Correct answer: increase the thickness.- A. placed in an electric field.
- B. moved in an electric field.
- C. placed in a magnetic field.
- D. moved in a magnetic field.
Explanation: The correct answer is Option D. When a coil is moved in a magnetic field, the magnetic flux through the coil changes, inducing an…
Correct answer: moved in a magnetic field.- A. low
- B. high
- C. varying
- D. constant
Explanation: The correct answer is Option C: varying. According to Faraday's law of electromagnetic induction, an electromotive force is induced in a…
Correct answer: varying234. If an electric motor is overloaded, then the magnitude of back electromotive force (e.m.f.) will
- A. increase
- B. decrease
- C. become zero
- D. remain the same
Explanation: When an electric motor is overloaded, it slows down due to the increased load.
Correct answer: decrease- A. Self-induction.
- B. Self-inductance.
- C. Mutual induction.
- D. Mutual inductance.
Explanation: The correct answer is mutual induction. This process involves the induction of electromotive force (EMF) in one coil due to a changing…
Correct answer: Mutual induction.- A. Lenz's law.
- B. Faraday's law.
- C. Ampere's law.
- D. Coulomb's law.
Explanation: The principle of an alternating current generator is based on Faraday's law of electromagnetic induction.
Correct answer: Faraday's law.- A. 0
- B. 1
- C. Less than 0
- D. More than 1
Explanation: The self-inductance of a straight wire carrying current is 0 because self-inductance arises from the wire's ability to create a magnetic…
Correct answer: 0- A. Lenz's law.
- B. Faraday's law.
- C. Ampere's law.
- D. Coulomb's law.
Explanation: Lenz's law is the correct answer because it specifically addresses the direction of induced e.m.f.
Correct answer: Lenz's law.- A. Increase voltage reduce current
- B. Increase current, reduce voltage
- C. Increase both voltage and current
- D. Increase both voltage and power
Explanation: Step-up transformers are used in long-distance electricity transmission to increase the voltage and decrease the current.
Correct answer: Increase voltage reduce current- A. current
- B. voltage
- C. resistance
- D. power
Explanation: The power remains constant. This means that the power input to the primary coil is equal to the power output from the secondary coil…
Correct answer: power