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Electromagnetic Induction Class 12 Physics MCQs 2026-27 | Chapter 6
Class 12 Physics • Chapter 6 • 2026–27
Electromagnetic Induction Class 12 Physics MCQs
60 MCQs with answers and concise explanations covering magnetic flux, Faraday’s laws, Lenz’s law, induced EMF/current, motional EMF, self-induction, mutual induction and application-based numerical reasoning.
Practise magnetic flux, Faraday’s laws, Lenz’s law, motional EMF, self-induction, mutual induction and application-based concepts.
How to use this MCQ bank: Attempt each question before checking the answer. For numerical MCQs, write the formula, substitution and unit first. For direction questions, identify whether the linked magnetic flux is increasing or decreasing before applying Lenz’s law.
2026–27 syllabus boundary: The current CBSE curriculum places electromagnetic induction, Faraday’s laws, induced EMF/current, Lenz’s law, self-induction and mutual induction in Chapter 6. AC generator and transformer are listed under Chapter 7: Alternating Current, so they are not mixed into the Chapter 6 core.
Question-design focus: Current 2026–27 practice resources repeatedly target Faraday’s law, Lenz’s law, magnetic-flux change, motional EMF, self-induction and mutual induction. This bank adds numerical, graph-slope, direction, induced-charge and misconception-based MCQs so students practise more than definition recall.
Section A — Electromagnetic Induction MCQs
Each question has one best answer. The explanations are intentionally concise so the page remains useful for rapid revision.
Q1
Electromagnetic induction is the phenomenon of production of induced EMF when
(A) the magnetic flux linked with a circuit changes
(B) the resistance of a circuit becomes zero
(C) the current remains constant
(D) the temperature of the circuit changes
Answer: (A) Induced EMF is produced when the magnetic flux linked with a circuit changes.
Q2
The SI unit of magnetic flux is
(A) tesla
(B) weber
(C) henry
(D) volt
Answer: (B) Magnetic flux is measured in weber (Wb).
Q3
For a plane surface in a uniform magnetic field, magnetic flux is
(A) BA sin θ
(B) B/A cos θ
(C) BA cos θ
(D) Bℓv
Answer: (C) ΦB = BA cos θ, where θ is the angle between B and the area vector.
Q4
Magnetic flux through a surface is maximum when the angle between B and the area vector is
(A) 0°
(B) 30°
(C) 60°
(D) 90°
Answer: (A) At θ = 0°, cos θ = 1, so ΦB = BA.
Q5
Magnetic flux through a plane surface is zero when the angle between B and the area vector is
(A) 0°
(B) 45°
(C) 60°
(D) 90°
Answer: (D) At θ = 90°, cos θ = 0.
Q6
Faraday's law for a coil of N turns is
(A) ε = NΦB
(B) ε = −N dΦB/dt
(C) ε = Bℓv only
(D) ε = IR/N
Answer: (B) The induced EMF equals the negative rate of change of flux linkage.
Q7
The negative sign in Faraday's law represents
(A) Ohm's law
(B) conservation of charge
(C) Lenz's law
(D) Joule's law
Answer: (C) The negative sign represents the direction required by Lenz's law.
Q8
If magnetic flux linked with a coil remains constant, the induced EMF is
(A) maximum
(B) zero
(C) infinite
(D) equal to resistance
Answer: (B) No change in flux means dΦB/dt = 0, so induced EMF is zero.
Q9
A coil has 200 turns and the magnetic flux through each turn changes by 0.01 Wb in 0.5 s. The average induced EMF magnitude is
(A) 2 V
(B) 4 V
(C) 8 V
(D) 10 V
Answer: (B) |ε| = N|ΔΦ|/Δt = 200×0.01/0.5 = 4 V.
Q10
Lenz's law is fundamentally a consequence of
(A) conservation of energy
(B) conservation of mass
(C) Newton's third law only
(D) Coulomb's law
Answer: (A) The induced current opposes the change that produces it, consistent with conservation of energy.
Q11
When the north pole of a bar magnet approaches a coil, the near face of the coil behaves as
(A) north pole to oppose the approach
(B) south pole to attract the magnet
(C) no magnetic pole
(D) a permanent north pole independent of motion
Answer: (A) The induced magnetic effect opposes the increase in flux caused by the approaching north pole.
Q12
If a magnet is moved faster toward a coil, the magnitude of induced EMF generally
(A) decreases
(B) increases
(C) becomes exactly zero
(D) remains unchanged in all cases
Answer: (B) A faster change in flux means a larger magnitude of dΦB/dt.
Q13
A conducting rod of length ℓ moves with speed v perpendicular to a uniform magnetic field B. The motional EMF is
(A) Bℓ/v
(B) Bv/ℓ
(C) Bℓv
(D) B/(ℓv)
Answer: (C) For the stated perpendicular geometry, ε = Bℓv.
Q14
A rod moves parallel to the magnetic field with velocity v. Its motional EMF due to B is
(A) Bℓv
(B) zero
(C) Bv/ℓ
(D) infinite
Answer: (B) For motion parallel to B, the magnetic force on charges q(v×B) is zero.
Q15
A rod of length 0.5 m moves at 4 m/s perpendicular to a 0.2 T field. Its motional EMF is
(A) 0.04 V
(B) 0.4 V
(C) 2.5 V
(D) 4 V
Answer: (B) ε = Bℓv = 0.2×0.5×4 = 0.4 V.
Q16
The direction of induced current in a closed conducting loop is determined by
(A) Lenz's law
(B) Ohm's law
(C) Kirchhoff's junction rule alone
(D) Newton's law of gravitation
Answer: (A) Lenz's law determines the direction of induced current so that the magnetic effect opposes the change in flux.
Q17
Induced EMF exists in a circuit only while
(A) the circuit has resistance
(B) the magnetic flux linked with it is changing
(C) the temperature is constant
(D) the current is constant
Answer: (B) A changing linked flux is required for induced EMF.
Q18
If the number of turns of a coil is doubled while the same flux changes at the same rate, induced EMF magnitude becomes
(A) half
(B) unchanged
(C) double
(D) four times
Answer: (C) Faraday's law gives |ε| = N|dΦ/dt|, so doubling N doubles EMF.
Q19
For a simple closed circuit of resistance R, the total induced charge for a flux change ΔΦ through an N-turn coil is
(A) NΔΦR
(B) NΔΦ/R
(C) NR/ΔΦ
(D) R/(NΔΦ)
Answer: (B) Using q = ∫I dt and Faraday's law, q = N|ΔΦ|/R for constant R.
Q20
The induced charge in a simple closed coil for a fixed change in flux is independent of
(A) number of turns
(B) change in flux
(C) resistance
(D) time taken for the flux change
Answer: (D) q = N|ΔΦ|/R does not contain the time interval.
Q21
A coil has 100 turns, resistance 5 Ω, and the flux per turn changes by 0.02 Wb. The total induced charge is
(A) 0.04 C
(B) 0.4 C
(C) 4 C
(D) 40 C
Answer: (B) q = NΔΦ/R = 100×0.02/5 = 0.4 C.
Q22
Self-induction refers to induction of EMF in a coil due to
(A) change of current in the same coil
(B) current in an unrelated distant circuit
(C) constant magnetic flux
(D) change of resistance only
Answer: (A) A changing current in a coil changes its own linked flux and induces an opposing EMF.
Q23
The SI unit of self-inductance is
(A) weber
(B) tesla
(C) henry
(D) farad
Answer: (C) Self-inductance is measured in henry (H).
Q24
The self-induced EMF in a coil of inductance L is
(A) ε = LI
(B) ε = −L dI/dt
(C) ε = L/I
(D) ε = IR
Answer: (B) The magnitude depends on the rate of change of current; the negative sign represents opposition to the change.
Q25
A 2 H inductor carries a current whose rate of change is 3 A/s. The magnitude of self-induced EMF is
(A) 1.5 V
(B) 2 V
(C) 5 V
(D) 6 V
Answer: (D) |ε| = L|dI/dt| = 2×3 = 6 V.
Q26
The energy stored in an ideal inductor carrying current I is
(A) LI
(B) 1/2 LI²
(C) L/I²
(D) 2LI²
Answer: (B) Magnetic energy stored in an inductor is U = 1/2 LI².
Q27
An inductor of 4 H carries 2 A. The stored magnetic energy is
(A) 4 J
(B) 8 J
(C) 16 J
(D) 32 J
Answer: (B) U = 1/2×4×(2²) = 8 J.
Q28
A long air-core solenoid has self-inductance proportional to
(A) N²
(B) 1/N²
(C) N only
(D) 1/N
Answer: (A) For a long solenoid, L = μ0N²A/ℓ, so L is proportional to N² when other quantities are fixed.
Q29
For a long air-core solenoid, increasing its length while keeping N and A fixed makes its inductance
(A) increase
(B) decrease
(C) unchanged
(D) infinite
Answer: (B) L = μ0N²A/ℓ, so increasing ℓ decreases L.
Q30
Mutual induction occurs when
(A) a changing current in one coil induces EMF in another coupled coil
(B) a constant current produces changing flux by itself
(C) two resistors are connected in parallel
(D) a capacitor is charged
Answer: (A) Changing current in one coil changes magnetic flux linked with another coil and induces EMF there.
Q31
The mutual-induced EMF in a secondary coil due to changing current in a primary coil is
(A) ε = −M dI/dt
(B) ε = MI
(C) ε = M/I
(D) ε = IR
Answer: (A) For mutual induction, ε₂ = −M dI₁/dt.
Q32
Two coils have mutual inductance 3 H. If current in the primary changes at 4 A/s, the induced EMF magnitude in the secondary is
(A) 0.75 V
(B) 7 V
(C) 12 V
(D) 16 V
Answer: (C) |ε| = M|dI/dt| = 3×4 = 12 V.
Q33
Mutual inductance between two coils generally becomes stronger when their magnetic coupling is
(A) reduced
(B) increased
(C) made zero
(D) made independent of geometry
Answer: (B) Better magnetic coupling generally increases the flux linkage of one coil due to current in the other.
Q34
If the current in the primary coil is steady, the mutual induced EMF in a nearby secondary coil is
(A) maximum
(B) zero, after the transient change has ended
(C) equal to the primary current
(D) infinite
Answer: (B) A steady current gives steady flux, so dI/dt and hence mutual-induced EMF are zero.
Q35
A coil is rotated in a uniform magnetic field. An induced EMF can be produced because
(A) its linked flux can change
(B) its resistance must become zero
(C) its charge becomes conserved
(D) its inductance must become infinite
Answer: (A) Rotation can change the angle between the field and the area vector, changing flux.
Q36
A loop of area 0.02 m² is in a 0.5 T field with its area vector parallel to B. Its flux is
(A) 0.001 Wb
(B) 0.01 Wb
(C) 0.02 Wb
(D) 0.05 Wb
Answer: (B) Φ = BA = 0.5×0.02 = 0.01 Wb.
Q37
If the same loop in Q36 is turned so that its area vector is perpendicular to B, its flux becomes
(A) 0.01 Wb
(B) 0.005 Wb
(C) 0
(D) 0.5 Wb
Answer: (C) Φ = BA cos 90° = 0.
Q38
Which change can produce electromagnetic induction in a stationary coil?
(A) changing the current in a nearby coil
(B) keeping all magnetic fields constant
(C) disconnecting no source and making no change
(D) keeping flux constant
Answer: (A) A changing current in a nearby coil changes the magnetic flux linked with the stationary coil.
Q39
A coil has 50 turns. Its flux per turn changes from 0.04 Wb to 0.01 Wb in 0.3 s. The magnitude of average induced EMF is
(A) 2 V
(B) 5 V
(C) 10 V
(D) 15 V
Answer: (B) |ε| = N|ΔΦ|/Δt = 50×0.03/0.3 = 5 V.
Q40
A magnetic field through a loop changes but the loop has an open gap. What is definitely produced during the change?
(A) No induced EMF
(B) Induced EMF, but no sustained conduction current through the open gap
(C) Only heat
(D) Only mechanical force
Answer: (B) A changing flux produces EMF; an open circuit prevents a continuous conduction current.
Q41
A student says, 'Lenz's law means induced current always opposes the magnetic field.' The best correction is
(A) it always opposes the change in flux, not necessarily the existing field
(B) it always supports the field
(C) it applies only to resistors
(D) it applies only when flux is zero
Answer: (A) Lenz's law concerns opposition to the change that produces the induction.
Q42
Which statement about magnetic force on a moving charge is relevant to motional induction?
(A) The magnetic force can separate charges in a moving conductor
(B) Magnetic force always does positive work on the charge
(C) Magnetic force is always parallel to velocity
(D) Magnetic force exists only when the charge is stationary
Answer: (A) In a moving conductor, q(v×B) can drive charge separation and contribute to motional EMF.
Q43
For an ideal inductor, when current is increasing, the self-induced EMF acts so as to
(A) support the increase in current
(B) oppose the increase in current
(C) make current infinite
(D) remove all resistance
Answer: (B) Lenz's law makes the induced EMF oppose the change in current.
Q44
A 10 H inductor experiences a current change of 0.2 A in 0.5 s. The magnitude of induced EMF is
(A) 0.4 V
(B) 2 V
(C) 4 V
(D) 10 V
Answer: (C) |ε| = LΔI/Δt = 10×0.2/0.5 = 4 V.
Q45
If the current in a primary coil decreases rapidly, the induced EMF in a nearby secondary coil is larger than for a slow decrease because
(A) the rate of change of current is larger
(B) mutual inductance becomes zero
(C) resistance disappears
(D) flux becomes constant
Answer: (A) Mutual-induced EMF magnitude is proportional to |dI/dt| for fixed M.
Q46
Which pair is correctly matched?
(A) Self-inductance — changing current in the same coil
(B) Mutual inductance — no magnetic coupling
(C) Magnetic flux — unit henry
(D) Motional EMF — B/I
Answer: (A) Self-inductance describes the induced EMF associated with changing current in the same coil.
Q47
Eddy currents are
(A) circulating induced currents in bulk conductors
(B) steady currents in ideal insulators
(C) currents that exist only in vacuum
(D) currents produced only by batteries
Answer: (A) Eddy currents are circulating currents induced within bulk conductors when magnetic flux changes.
Q48
Which application is based on the opposing effect of induced currents and is best treated here as an enrichment example?
(A) eddy-current braking
(B) electrostatic shielding
(C) capacitor charging by DC
(D) resistance measurement only
Answer: (A) Eddy-current braking uses the opposing effect of induced currents; it is enrichment rather than a named core subtopic here.
Q49
A correct problem-solving sequence for an induction numerical is
(A) identify flux change → choose Faraday/motional/self/mutual relation → substitute units → check direction/sign where required
(B) memorise answer → ignore units → calculate
(C) use Ohm's law first in every case → ignore flux
(D) choose any formula containing B → stop
Answer: (A) Induction problems should begin with the physical cause of flux/current change, then use the appropriate relation and check units and direction.
Q50
A coil has N turns and its flux per turn changes by ΔΦ in time Δt. If N is doubled while ΔΦ is halved and Δt is unchanged, the average induced EMF magnitude becomes
(A) half
(B) unchanged
(C) double
(D) four times
Answer: (B) Since |ε| = N|ΔΦ|/Δt, doubling N and halving ΔΦ leave the product NΔΦ unchanged.
Q51
A coil of fixed area and orientation is placed in a magnetic field whose magnitude decreases uniformly with time. The magnitude of induced EMF is
(A) zero
(B) constant
(C) infinite
(D) random
Answer: (B) With fixed geometry, a uniform rate of change of B gives a constant rate of change of flux and hence constant induced EMF magnitude.
Q52
A 50-turn coil has flux per turn changing from +0.04 Wb to −0.04 Wb in 0.20 s. The magnitude of average induced EMF is
(A) 10 V
(B) 20 V
(C) 40 V
(D) 80 V
Answer: (B) The flux change per turn is 0.08 Wb, so |ε| = 50×0.08/0.20 = 20 V.
Q53
A 100-turn coil of resistance 2 Ω experiences a total induced charge of 0.5 C. The magnitude of the change in flux per turn is
(A) 0.001 Wb
(B) 0.005 Wb
(C) 0.01 Wb
(D) 0.1 Wb
Answer: (C) Using q = N|ΔΦ|/R, |ΔΦ| = qR/N = 0.5×2/100 = 0.01 Wb.
Q54
A 5 H inductor carries 2 A and its current becomes zero uniformly in 0.5 s. The magnitude of average self-induced EMF is
(A) 5 V
(B) 10 V
(C) 20 V
(D) 25 V
Answer: (C) |ε| = L|ΔI|/Δt = 5×2/0.5 = 20 V.
Q55
If the current through an ideal inductor is doubled, the energy stored in it becomes
(A) half
(B) double
(C) four times
(D) eight times
Answer: (C) Since U = 1/2 LI², doubling I makes U four times as large.
Q56
A current-time graph for a coil is horizontal over a time interval. The self-induced EMF during that interval is
(A) maximum
(B) zero
(C) negative infinity
(D) equal to LI
Answer: (B) A horizontal I–t graph means dI/dt = 0, so ε = −L dI/dt = 0.
Q57
A flux-time graph has a straight-line segment with a constant negative slope. For a fixed N-turn coil, the induced EMF magnitude during that segment is
(A) zero
(B) constant
(C) increasing linearly
(D) decreasing linearly
Answer: (B) Faraday's law makes induced EMF proportional to the magnitude of the slope dΦ/dt.
Q58
A coil is rotated through 180° in a uniform magnetic field, changing its flux per turn from +BA to −BA. The magnitude of the flux change per turn is
(A) 0
(B) BA
(C) 2BA
(D) 4BA
Answer: (C) ΔΦ = (−BA) − (+BA) = −2BA, so its magnitude is 2BA.
Q59
Which statement correctly distinguishes induced EMF from induced current?
(A) EMF requires a closed circuit, but current does not
(B) A changing flux can produce EMF in an open circuit, while conduction current requires a closed path
(C) EMF and current are always identical quantities
(D) Current can exist without any electric or magnetic cause
Answer: (B) A changing flux can establish an induced EMF even in an open circuit; a sustained conduction current needs a closed conducting path.
Q60
Under the current CBSE 2026–27 syllabus mapping, AC generator and transformer are studied under
(A) Chapter 4: Moving Charges and Magnetism
(B) Chapter 5: Magnetism and Matter
(C) Chapter 6: Electromagnetic Induction
(D) Chapter 7: Alternating Current
Answer: (D) The current CBSE curriculum lists AC generator and transformer under Chapter 7: Alternating Current, while Chapter 6 lists electromagnetic induction, Faraday's laws, induced EMF/current, Lenz's law, self-induction and mutual induction.
Quick Answer Key
| Q | Ans. | Q | Ans. | Q | Ans. | Q | Ans. | Q | Ans. |
|---|---|---|---|---|---|---|---|---|---|
| 1 | A | 2 | B | 3 | C | 4 | A | 5 | D |
| 6 | B | 7 | C | 8 | B | 9 | B | 10 | A |
| 11 | A | 12 | B | 13 | C | 14 | B | 15 | B |
| 16 | A | 17 | B | 18 | C | 19 | B | 20 | D |
| 21 | B | 22 | A | 23 | C | 24 | B | 25 | D |
| 26 | B | 27 | B | 28 | A | 29 | B | 30 | A |
| 31 | A | 32 | C | 33 | B | 34 | B | 35 | A |
| 36 | B | 37 | C | 38 | A | 39 | B | 40 | B |
| 41 | A | 42 | A | 43 | B | 44 | C | 45 | A |
| 46 | A | 47 | A | 48 | A | 49 | A | 50 | B |
| 51 | B | 52 | B | 53 | C | 54 | C | 55 | C |
| 56 | B | 57 | B | 58 | C | 59 | B | 60 | D |
What These MCQs Cover
Core: magnetic flux and area-vector angle • causes of flux change • Faraday’s laws • Lenz’s law • induced EMF/current • motional EMF • induced charge • self-induction • inductance and stored energy • mutual induction. Application: numerical, proportional, graph-slope and direction questions. Enrichment: eddy currents. Scope check: AC generator and transformer are kept with Chapter 7.
Exam Traps to Avoid
1. In Φ = BA cos θ, θ is measured from the area vector, not the plane itself.
2. Lenz’s law opposes the change in flux, not necessarily the magnetic field already present.
3. A changing flux can produce EMF even when the circuit is open; a closed conducting path is required for a sustained conduction current.
4. For motional EMF, use the actual geometry before applying Bℓv.
5. Self-induction involves the same coil; mutual induction involves coupled coils.
Continue Chapter 6 Preparation
Frequently Asked Questions
What are the main topics in Electromagnetic Induction Class 12 Physics?
The current CBSE 2026–27 Chapter 6 scope includes electromagnetic induction, Faraday’s laws, induced EMF and current, Lenz’s law, self-induction and mutual induction.
The current CBSE 2026–27 Chapter 6 scope includes electromagnetic induction, Faraday’s laws, induced EMF and current, Lenz’s law, self-induction and mutual induction.
Which formula is used for induced EMF?
For an N-turn coil, Faraday’s law is ε = −N dΦB/dt; for an average value over a finite interval, use εavg = −NΔΦB/Δt.
For an N-turn coil, Faraday’s law is ε = −N dΦB/dt; for an average value over a finite interval, use εavg = −NΔΦB/Δt.
What is the difference between self-induction and mutual induction?
Self-induction is induced EMF in a coil due to change in its own current; mutual induction is induced EMF in one coil due to changing current in another coupled coil.
Self-induction is induced EMF in a coil due to change in its own current; mutual induction is induced EMF in one coil due to changing current in another coupled coil.
Are AC generator and transformer in Chapter 6 for CBSE 2026–27?
No. The current CBSE syllabus lists AC generator and transformer under Chapter 7: Alternating Current.
No. The current CBSE syllabus lists AC generator and transformer under Chapter 7: Alternating Current.
Source discipline: These are original Learn Revise Hub practice MCQs. The official CBSE 2026–27 curriculum and official Class XII SQP/MS are the authority for syllabus scope and assessment documents; third-party resources were used only for search-intent and question-format research, not as syllabus authority.
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