CUET UG Physics Booster Test 3-Mutual and Self-Inductance -

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CUET UG Physics Booster Test 3-Mutual and Self-Inductance

⏱️ 30 Minutes

❓ 20 Questions

📌 Answers are locked once submitted — results and explanations appear at the end.

CUET UG Physics Booster Test 3-Mutual and Self-Inductance

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QUESTION 1 OF 20

Consider the following statements regarding the concept of inductance. Which of the above statements are correct?
1. Flux linkage NΦ_B is strictly proportional to current I only if the geometry of the coil does not vary with time.
2. If the coil shape shrinks or stretches, dΦ_B/dt still depends purely on dI/dt.
3. Inductance is a vector quantity.
4. Inductance behaves similarly to capacitance, which depends on geometry and intrinsic material properties.

Answer Review

1 Consider the following statements regarding the concept of inductance. Which of the above statements are correct?
1. Flux linkage NΦ_B is strictly proportional to current I only if the geometry of the coil does not vary with time.
2. If the coil shape shrinks or stretches, dΦ_B/dt still depends purely on dI/dt.
3. Inductance is a vector quantity.
4. Inductance behaves similarly to capacitance, which depends on geometry and intrinsic material properties.

A 1, 2

B 1, 4

C 2, 3, 4

D 1, 3

💡 Short Explanation

�� Fixed geometry gives NΦ ∝ I. �� Variable geometry introduces additional effects. �� Inductance is scalar.

✅ Correct Answer Explanation

Statement 1 is correct because the relation NΦ = LI assumes the geometry remains unchanged. → Statement 2 is incorrect because when geometry changes, flux changes due to both current variation and geometric variation. → Statement 3 is incorrect because inductance is a scalar quantity. → Statement 4 is correct because inductance, like capacitance, depends on geometry and material properties.

❓ Why Other Options Are Incorrect

�� Option A → Contains incorrect Statement 2.
�� Option C → Contains incorrect Statements 2 and 3.
�� Option D → Contains incorrect Statement 3.

🎯 Strategy

Used

�� Elimination

Application:

�� Identify statements violating the definition of inductance.

Final Logic:

�� Only Statements 1 and 4 are correct.

🧠 Memory Trick

"Fixed Shape → NΦ = LI."

📚 Class XII – Physics Part I – Chapter: Electromagnetic Induction – Topic: Concept of Inductance

2 Choose the correct statements about the geometric and material dependency of inductance
1. Self-inductance of a solenoid is directly proportional to its cross-sectional area.
2. The relative permeability μr of the core material acts as an intrinsic property affecting inductance.
3. Self-inductance depends inversely on the square of the number of turns per unit length.
4. Mutual inductance between two coils is completely independent of their relative orientation.

A 1, 2

B 2, 3

C 1, 2, 4

D 3, 4

💡 Short Explanation

�� L ∝ A. �� L ∝ μr. �� L ∝ n².

✅ Correct Answer Explanation

Statement 1 is correct because: L = μ₀n²Al Hence L is directly proportional to area A. → Statement 2 is correct because permeability of the core directly affects inductance. → Statement 3 is incorrect because inductance is directly proportional to n². → Statement 4 is incorrect because mutual inductance strongly depends on relative orientation.

❓ Why Other Options Are Incorrect

�� Option B → Contains incorrect Statement 3.
�� Option C → Contains incorrect Statement 4.
�� Option D → Both statements are incorrect.

🎯 Strategy

Used

�� Elimination

Application:

�� Check proportionalities from the inductance formula.

Final Logic:

�� Only Statements 1 and 2 are correct.

🧠 Memory Trick

"A, μ, n² increase L."

📚 Class XII – Physics Part I – Chapter: Electromagnetic Induction – Topic: Factors Affecting Inductance

3 In defining the unit of inductance, the Henry:

A one Henry equals one Weber per second

B the unit is dimensionally equivalent to the product of magnetic flux and current

C it represents the scalar constant of proportionality between total flux linkage and the current producing it

D its dimensions are [M L T⁻² A⁻¹]

💡 Short Explanation

�� NΦ = LI. �� L is measured in Henry. �� Henry measures inductance.

✅ Correct Answer Explanation

Inductance is defined through: NΦ = LI → The proportionality constant L is called inductance and its SI unit is Henry.

❓ Why Other Options Are Incorrect

�� Option A → Henry = Weber/Ampere, not Weber/second.
�� Option B → L = Flux/Current, not Flux × Current.
�� Option D → Incorrect dimensions.

🎯 Strategy

Used

�� Formula Recognition

Application:

�� Use the defining equation NΦ = LI.

Final Logic:

�� Henry measures the proportionality constant L.

🧠 Memory Trick

"Henry = Flux Linkage ÷ Current."

📚 Class XII – Physics Part I – Chapter: Electromagnetic Induction – Topic: Unit of Inductance

4 If the energy stored in an inductor is U = ½LI², the dimensions of inductance L must satisfy the equation dimensionally. Thus, if energy has dimensions [ML²T⁻²] and current has dimensions [A], the dimensions of inductance will be

A [ML²T⁻²A⁻¹]

B [ML²T⁻²A⁻²]

C [ML²T⁻³A⁻²]

D [ML²T⁻¹A⁻²]

💡 Short Explanation

�� U = ½LI². �� Divide energy dimensions by A². �� Obtain dimensions of L.

✅ Correct Answer Explanation

[L] = [U]/[I²] = [ML²T⁻²]/[A²] = [ML²T⁻²A⁻²]

❓ Why Other Options Are Incorrect

�� Option A → Missing one current dimension.
�� Option C → Wrong time dimension.
�� Option D → Wrong time dimension.

🎯 Strategy

Used

�� Dimensional Analysis

Application:

�� Rearrange U = ½LI² dimensionally.

Final Logic:

�� L = [ML²T⁻²A⁻²].

🧠 Memory Trick

"Energy ÷ Current²."

📚 Class XII – Physics Part I – Chapter: Electromagnetic Induction – Topic: Dimensions of Inductance

5 The mutual inductance of a pair of coils is:

A is fixed regardless of the distance between them as long as their shapes remain constant

B depends on their separation as well as their relative orientation

C is purely an intrinsic property of the primary coil

D is independent of the permeability of the intervening medium

💡 Short Explanation

�� Distance matters. �� Orientation matters. �� Medium matters.

✅ Correct Answer Explanation

Mutual inductance depends on: • Relative orientation • Distance between coils • Geometry of coils • Permeability of medium Hence Option B is correct.

❓ Why Other Options Are Incorrect

�� Option A → Separation affects flux linkage.
�� Option C → Depends on both coils.
�� Option D → Permeability affects mutual inductance.

🎯 Strategy

Used

�� Elimination

Application:

�� Identify factors affecting mutual inductance.

Final Logic:

�� Relative position and medium affect M.

🧠 Memory Trick

"Distance + Direction + Medium."

📚 Class XII – Physics Part I – Chapter: Electromagnetic Induction – Topic: Mutual Inductance

6 If the mutual inductance between two co-axial concentric circular coils of radii r₁ and r₂ (r₁ << r₂) is 2.0 × 10⁻⁸ H, what will be the new mutual inductance if the radius of the inner coil is doubled and the radius of the outer coil is halved?

A 2.0 × 10⁻⁸ H

B 1.6 × 10⁻⁷ H

C 8.0 × 10⁻⁸ H

D 4.0 × 10⁻⁸ H

💡 Short Explanation

�� M ∝ r₁²/r₂. �� r₁ doubled → ×4. �� r₂ halved → ×2.

✅ Correct Answer Explanation

M ∝ r₁²/r₂ → New value: M' = M × 4 × 2 = 8M = 8(2.0 × 10⁻⁸) = 1.6 × 10⁻⁷ H

❓ Why Other Options Are Incorrect

�� Option A → Ignores geometry change.
�� Option C → Only factor 4 considered.
�� Option D → Only factor 2 considered.

🎯 Strategy

Used

�� Proportionality Analysis

Application:

�� Use dependence M ∝ r₁²/r₂.

Final Logic:

�� Total multiplication factor = 8.

🧠 Memory Trick

"Radius² dominates."

📚 Class XII – Physics Part I – Chapter: Electromagnetic Induction – Topic: Mutual Inductance of Circular Coils

7 Choose the incorrect statement about calculating co-axial solenoid flux

A We assume the magnetic field generated by the outer solenoid is uniform throughout the inner solenoid.

B The flux linked with the outer solenoid due to the inner solenoid is assumed to be confined solely inside the inner solenoid.

C The total flux linkage with the outer solenoid S₂ is exactly N₂Φ₂ = M₂₁I₁.

D The field of the inner solenoid is assumed to spread uniformly across the entire cross-sectional area of the outer solenoid.

💡 Short Explanation

�� Field of inner solenoid is confined. �� Not uniform over entire outer area. �� Long-solenoid approximation used.

✅ Correct Answer Explanation

The field produced by the inner solenoid is essentially confined to its own cross-sectional area. → Therefore, it is incorrect to assume it spreads uniformly throughout the larger outer solenoid.

❓ Why Other Options Are Incorrect

�� Option A → Standard assumption.
�� Option B → Correct approximation.
�� Option C → Correct definition of M₂₁.

🎯 Strategy

Used

�� Elimination

Application:

�� Check assumptions used in mutual inductance derivation.

Final Logic:

�� Statement D contradicts field confinement.

🧠 Memory Trick

"Inner Field Stays Inside."

📚 Class XII – Physics Part I – Chapter: Electromagnetic Induction – Topic: Co-axial Solenoids

8 Match List I with List II concerning parameters of long co-axial solenoids and their effect on mutual inductance

List I	List II
1. Doubling number of turns per unit length of both solenoids ((n_1, n_2))	a. M increases by a factor of 4
2. Doubling the radius of the inner solenoid ((r_1))	c. M increases by a factor of 4 (due to square of radius)
3. Doubling the length ((l))	b. M increases by a factor of 2
4. Inserting a core of relative permeability ((\mu_r))	d. M is scaled by (\mu_r)

A 1-a, 2-c, 3-b, 4-d

B 1-b, 2-a, 3-c, 4-d

C 1-d, 2-b, 3-a, 4-c

D 1-a, 2-d, 3-b, 4-c

💡 Short Explanation

�� M ∝ n₁n₂r₁²lμr. �� Apply proportionality. �� Match factors.

✅ Correct Answer Explanation

1 → a because doubling both n₁ and n₂ gives 2×2 = 4 times. → 2 → c because area ∝ r₁², so doubling r₁ gives fourfold increase. → 3 → b because M ∝ l. → 4 → d because M ∝ μr.

❓ Why Other Options Are Incorrect

�� Option B → Incorrect radius and length matching.
�� Option C → Multiple mismatches.
�� Option D → μr incorrectly matched.

🎯 Strategy

Used

�� Option Grouping

Application:

�� Use M ∝ μrn₁n₂πr₁²l.

Final Logic:

�� Direct proportionality gives the correct mapping.

🧠 Memory Trick

"n₁n₂, r², l, μ."

📚 Class XII – Physics Part I – Chapter: Electromagnetic Induction – Topic: Mutual Inductance Factors

9 If a general equality holds for the mutual inductance between two coils, M₁₂ = M₂₁ = M. Thus, if a changing current I₁ in coil 1 induces an emf ε₂ in coil 2, and similarly a changing current I₂ in coil 2 induces ε₁ in coil 1, the ratio of the emfs (ε₁/ε₂) will be

A (dI₂/dt)/(dI₁/dt)

B (dI₁/dt)/(dI₂/dt)

C M₁₂/M₂₁

D 1

💡 Short Explanation

�� ε₁ = -M(dI₂/dt). �� ε₂ = -M(dI₁/dt). �� Divide the two expressions.

✅ Correct Answer Explanation

ε₁ = -M(dI₂/dt) ε₂ = -M(dI₁/dt) Therefore ε₁/ε₂ = (dI₂/dt)/(dI₁/dt)

❓ Why Other Options Are Incorrect

�� Option B → Reciprocal ratio.
�� Option C → Equals 1 but not the emf ratio.
�� Option D → True only if both current rates are equal.

🎯 Strategy

Used

�� Substitution

Application:

�� Use mutual induction equations.

Final Logic:

�� Cancel M and take ratio.

🧠 Memory Trick

"Emf follows other coil's dI/dt."

📚 Class XII – Physics Part I – Chapter: Electromagnetic Induction – Topic: Reciprocity Theorem

10 Consider the following statements on practical calculation utility statements regarding M₁₂ = M₂₁. Which one is correct?
1. It allows us to bypass the complex integration required to find flux across a non-uniform field.
2. It is mostly used when calculating the flux of a long inner solenoid over a short outer solenoid.
3. When an inner solenoid is very short, finding flux linkage with the outer solenoid is extremely difficult.
4. The equality applies only when the two coils have identical geometries.

A 1, 3

B 2, 4

C 1, 2, 3

D 3, 4

💡 Short Explanation

�� Reciprocity simplifies calculations. �� Short-solenoid field is non-uniform. �� Equality is general.

✅ Correct Answer Explanation

Statement 1 is correct because reciprocity avoids difficult flux calculations. → Statement 2 is incorrect because the theorem is not restricted to that specific arrangement. → Statement 3 is correct because direct flux linkage computation becomes difficult. → Statement 4 is incorrect because reciprocity is general and does not require identical geometries.

❓ Why Other Options Are Incorrect

�� Option B → Contains incorrect Statements 2 and 4.
�� Option C → Contains incorrect Statement 2.
�� Option D → Contains incorrect Statement 4.

🎯 Strategy

Used

�� Elimination

Application:

�� Identify the statements consistent with reciprocity theorem.

Final Logic:

�� Only Statements 1 and 3 are correct.

🧠 Memory Trick

"Reciprocity Saves Calculations."

📚 Class XII – Physics Part I – Chapter: Electromagnetic Induction – Topic: Reciprocity Theorem

11 Varying current in a single coil and the resulting flux change:

A Isolated coil, Self-induction

B Neighbouring coil, Mutual induction

C Primary coil, Capacitance

D Secondary coil, Resistance

💡 Short Explanation

�� Same coil involved. �� Flux changes due to its own current. �� Produces self-induced emf.

✅ Correct Answer Explanation

Self-induction occurs when a changing current in a coil changes the magnetic flux linked with the same coil. → The resulting induced emf appears in the same isolated coil.

❓ Why Other Options Are Incorrect

�� Option B → Describes mutual induction.
�� Option C → Capacitance is unrelated.
�� Option D → Resistance is unrelated to induction.

🎯 Strategy

Used

�� Contextual Matching

Application:

�� Identify the phenomenon associated with a single coil.

Final Logic:

�� Same coil + changing flux = Self-induction.

🧠 Memory Trick

"Self = Same Coil."

📚 Class XII – Physics Part I – Chapter: Electromagnetic Induction – Topic: Self-Induction

12 If the current in an isolated circuit falls from 10.0 A to 0.0 A in 0.2 s, and this induces an average back emf of 400 V, what will be the self-inductance coefficient L of the circuit?

A 4.0 H

B 8.0 H

C 2.0 H

D 80.0 H

💡 Short Explanation

�� ε = L|dI/dt|. �� Calculate current change rate. �� Find L.

✅ Correct Answer Explanation

ε = L |dI/dt| 400 = L × (10/0.2) 400 = 50L L = 8 H

❓ Why Other Options Are Incorrect

�� Option A → Half the correct value.
�� Option C → One-fourth the correct value.
�� Option D → Ten times larger.

🎯 Strategy

Used

�� Substitution

Application:

�� Apply ε = L(dI/dt).

Final Logic:

�� L = 400/50 = 8 H.

🧠 Memory Trick

"L = ε ÷ (dI/dt)."

📚 Class XII – Physics Part I – Chapter: Electromagnetic Induction – Topic: Self-Induced EMF

13 In a situation where the general currents flow simultaneously in two nearby coils (coil 1 and coil 2):

A the total flux linked with coil 1 is independent of the current in coil 2

B the total flux linked with coil 1 is the sum of fluxes N₁Φ₁ = M₁₁I₁ + M₁₂I₂

C the back emf only opposes the current from the secondary coil

D the self-inductance L₁ is entirely negated by the mutual inductance

💡 Short Explanation

�� Flux comes from both currents. �� Self and mutual contributions add. �� Superposition principle applies.

✅ Correct Answer Explanation

Coil 1 experiences flux due to: • Its own current I₁ • Current I₂ in the neighbouring coil Hence, N₁Φ₁ = M₁₁I₁ + M₁₂I₂

❓ Why Other Options Are Incorrect

�� Option A → Ignores mutual induction.
�� Option C → Back emf opposes all flux changes.
�� Option D → Mutual inductance does not cancel self-inductance.

🎯 Strategy

Used

�� Formula Recognition

Application:

�� Use total flux linkage expression.

Final Logic:

�� Total flux = Self flux + Mutual flux.

🧠 Memory Trick

"Self + Mutual = Total."

📚 Class XII – Physics Part I – Chapter: Electromagnetic Induction – Topic: Coupled Circuits

14 Choose the correct statements concerning the physical interpretation of back emf
Statements:
1. It is the electromagnetic analogue of momentum.
2. It requires work to be done to establish a steady current.
3. Electrical inertia (L) opposes both the growth and decay of current.
4. The potential energy stored is purely electrostatic.

A 2, 3

B 1, 4

C 1, 2, 3

D 3, 4

💡 Short Explanation

�� Inductance behaves like inertia. �� Current changes are resisted. �� Stored energy is magnetic.

✅ Correct Answer Explanation

Statement 1 is incorrect because inductance is analogous to mass (inertia), not momentum. → Statement 2 is correct because work must be done against back emf. → Statement 3 is correct because inductance opposes both rise and fall of current. → Statement 4 is incorrect because the stored energy is magnetic, not electrostatic.

❓ Why Other Options Are Incorrect

�� Option B → Both statements are incorrect.
�� Option C → Contains incorrect Statement 1.
�� Option D → Contains incorrect Statement 4.

🎯 Strategy

Used

�� Elimination

Application:

�� Compare electrical and mechanical analogies.

Final Logic:

�� Only Statements 2 and 3 are correct.

🧠 Memory Trick

"Inductor Resists Change."

📚 Class XII – Physics Part I – Chapter: Electromagnetic Induction – Topic: Back EMF

15 The mathematical formulation for self-inductance of a long solenoid:
1. suggests that inductance is inversely proportional to its length if total turns N is kept constant
2. shows that L = μ₀nAl, meaning it depends linearly on the number of turns per unit length
3. proves that cross-sectional area has no effect on inductance
4. requires the inclusion of edge effects for exact calculation
Choose correct:

A 1

B 2

C 3

D 4

💡 Short Explanation

�� L = μ₀N²A/l. �� For constant N, L ∝ 1/l. �� Area affects inductance.

✅ Correct Answer Explanation

For a long solenoid: L = μ₀N²A/l → If N is fixed, increasing length decreases inductance. → Hence L is inversely proportional to l.

❓ Why Other Options Are Incorrect

�� Option B → Correct formula contains n², not n.
�� Option C → L is directly proportional to area.
�� Option D → Standard derivation neglects edge effects.

🎯 Strategy

Used

�� Formula Recognition

Application:

�� Analyze proportionality from the formula.

Final Logic:

�� Fixed N gives L ∝ 1/l.

🧠 Memory Trick

"Longer Solenoid → Smaller L."

📚 Class XII – Physics Part I – Chapter: Electromagnetic Induction – Topic: Self-Inductance of Solenoid

16 Choose the incorrect statement regarding the effects of core permeability:

A Placing soft iron inside a solenoid drastically increases its self-inductance.

B The relative permeability μr is a dimensionless multiplying factor for inductance calculations.

C The formula L = μrμ₀n²Al is valid for a solenoid filled with a magnetic material.

D The mutual inductance between two co-axial solenoids is unaffected by the presence of a permeable core medium.

💡 Short Explanation

�� Permeability affects flux. �� Both self and mutual inductance increase. �� Soft iron enhances coupling.

✅ Correct Answer Explanation

Mutual inductance depends on magnetic flux linkage. → Increasing permeability increases flux for the same current. → Therefore mutual inductance increases when a permeable core is introduced.

❓ Why Other Options Are Incorrect

�� Option A → Correct statement.
�� Option B → μr is dimensionless.
�� Option C → Correct modified formula.

🎯 Strategy

Used

�� Elimination

Application:

�� Check dependence on permeability.

Final Logic:

�� Higher μr increases both L and M.

🧠 Memory Trick

"More μ → More Flux → More M."

📚 Class XII – Physics Part I – Chapter: Electromagnetic Induction – Topic: Magnetic Core Effects

17 If the general case of simultaneously varying currents in two nearby coils is analyzed, the induced emf in coil 1 depends on both its self-inductance L₁ and mutual inductance M₁₂. Thus, if currents I₁ and I₂ are changing, the total induced emf ε₁ in coil 1 will be

A -L₁(dI₁/dt) - M₁₂(dI₂/dt)

B L₁(dI₁/dt) + M₁₂(dI₂/dt)

C -L₁(dI₂/dt) - M₁₂(dI₁/dt)

D -M₁₂(dI₁/dt)

💡 Short Explanation

�� Self-induced term present. �� Mutual-induced term present. �� Both obey Lenz's law.

✅ Correct Answer Explanation

Self-induced emf: -L₁(dI₁/dt) → Mutual-induced emf: -M₁₂(dI₂/dt) → Total emf: ε₁ = -L₁(dI₁/dt) - M₁₂(dI₂/dt)

❓ Why Other Options Are Incorrect

�� Option B → Wrong sign.
�� Option C → Interchanges currents.
�� Option D → Omits self-induction term.

🎯 Strategy

Used

�� Formula Recognition

Application:

�� Add self and mutual emf contributions.

Final Logic:

�� Total emf = Self + Mutual opposition terms.

🧠 Memory Trick

"Self + Mutual, Both Negative."

📚 Class XII – Physics Part I – Chapter: Electromagnetic Induction – Topic: Coupled Circuits

18 Consider the statements regarding energy in current growth. Choose the correct statements.
1. The power required to build up current is given by dW/dt = εI.
2. Ignoring resistive losses, the work done integrates to ½LI².
3. This stored magnetic energy is exactly analogous to mechanical kinetic energy ½mv².
4. The term L is mathematically equivalent to velocity in mechanics.

A 1, 2, 3

B 2, 3, 4

C 1, 3

D 1, 2, 4

💡 Short Explanation

�� Power = εI. �� Energy = ½LI². �� Magnetic energy parallels kinetic energy.

✅ Correct Answer Explanation

Statement 1 is correct because electrical power against back emf is εI. → Statement 2 is correct because integration gives: U = ½LI² → Statement 3 is correct because: ½LI² ↔ ½mv² → Statement 4 is incorrect because L corresponds to mass, not velocity.

❓ Why Other Options Are Incorrect

�� Option B → Contains incorrect Statement 4.
�� Option C → Omits correct Statement 2.
�� Option D → Contains incorrect Statement 4.

🎯 Strategy

Used

�� Elimination

Application:

�� Use mechanical-electrical analogy.

Final Logic:

�� L ↔ m, I ↔ v.

🧠 Memory Trick

"L is Mass, I is Speed."

📚 Class XII – Physics Part I – Chapter: Electromagnetic Induction – Topic: Magnetic Energy Storage

19 Match List I with List II regarding energy expressions and concepts

List I	List II
1. u_B	a. B²/2μ₀
2. U_B	c. ½LI²
3. u_E	b. ½ε₀E²
4. V	d. Volume containing the flux

A 1-a, 2-c, 3-b, 4-d

B 1-b, 2-a, 3-d, 4-c

C 1-c, 2-d, 3-a, 4-b

D 1-d, 2-b, 3-c, 4-a

💡 Short Explanation

�� u_B = magnetic energy density. �� U_B = magnetic energy. �� u_E = electric energy density.

✅ Correct Answer Explanation

1 → a because: u_B = B²/2μ₀ → 2 → c because: U_B = ½LI² → 3 → b because: u_E = ½ε₀E² → 4 → d because V denotes volume.

❓ Why Other Options Are Incorrect

�� Option B → Energy density assignments incorrect.
�� Option C → Multiple mismatches.
�� Option D → Incorrect formula mapping.

🎯 Strategy

Used

�� Option Grouping

Application:

�� Match each symbol with its standard expression.

Final Logic:

�� Standard energy relations give the correct pairing.

🧠 Memory Trick

"u_B–B², u_E–E²."

📚 Class XII – Physics Part I – Chapter: Electromagnetic Induction – Topic: Energy Density

20 Energy density in a magnetic field is proportional to which of the following, and to which field does it correspond?

A B², Magnetic Field

B E², Magnetic Field

C 1/B², Electric Field

D 1/E², Electric Field

💡 Short Explanation

�� Magnetic energy density ∝ B². �� Electric energy density ∝ E². �� Inverse-square options are incorrect.

✅ Correct Answer Explanation

Magnetic energy density: u_B = B²/(2μ₀) → Therefore magnetic energy density is proportional to B².

❓ Why Other Options Are Incorrect

�� Option B → E² corresponds to electric field energy density.
�� Option C → Incorrect inverse-square dependence.
�� Option D → Incorrect inverse-square dependence.

🎯 Strategy

Used

�� Formula Recognition

Application:

�� Recall energy density formulas.

Final Logic:

�� Magnetic energy density varies as B².

🧠 Memory Trick

"Magnetic → B²."

📚 Class XII – Physics Part I – Chapter: Electromagnetic Induction – Topic: Magnetic Energy Density

CUET UG Physics Booster Test 3-Mutual and Self-Inductance

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