CUET UG Physics Booster Test 2-Transformers and Energy Transmission -

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CUET UG Physics Booster Test 2-Transformers and Energy Transmission

⏱️ 30 Minutes

❓ 20 Questions

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

CUET UG Physics Booster Test 2-Transformers and Energy Transmission

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QUESTION 1 OF 20

Identify the incorrect statement about electromagnetic induction in transformers

Answer Review

1 Identify the incorrect statement about electromagnetic induction in transformers

A The device relies on mutual induction between two insulated coils.

B It can change an alternating voltage to a greater or smaller value.

C It transforms direct current voltages easily and efficiently.

D An alternating current in the primary produces an alternating magnetic flux.

💡 Short Explanation

�� Transformers operate on mutual induction. �� Mutual induction requires changing magnetic flux. �� Direct current does not continuously produce changing flux.

✅ Correct Answer Explanation

A transformer works on the principle of mutual induction between primary and secondary coils. An alternating current in the primary coil produces a continuously changing magnetic flux in the iron core. This varying flux induces emf in the secondary coil. Therefore transformers can increase or decrease AC voltage levels. Direct current produces a constant magnetic field after the initial switching period. Since electromagnetic induction requires changing magnetic flux, a transformer cannot efficiently transform direct current voltages. Hence option C is the incorrect statement.

❓ Why Other Options Are Incorrect

�� Option A → Correct because transformers operate through mutual induction between insulated primary and secondary coils.
�� Option B → Correct because transformers can function as step-up or step-down devices.
�� Option D → Correct because alternating current produces alternating magnetic flux in the core.

🎯 Strategy

Used

Elimination

Application:

�� Identify statements consistent with transformer operation and eliminate them.

Final Logic:

�� Since transformers require changing magnetic flux, DC cannot be transformed efficiently.

🧠 Memory Trick

Transformer = AC only

📚 Class XII – Physics Part I – Chapter: Alternating Current – Topic: Transformer and Mutual Induction

2 Match List I with List II

List I	List II
1. Primary Coil	a. Often designated as the input coil
2. Secondary Coil	b. Either on top of each other or on separate limbs
3. Soft-iron core	c. Often designated as the output coil
4. Winding arrangement	d. Provides magnetic linkage for alternating flux

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

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

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

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

💡 Short Explanation

Primary coil acts as the input coil. Secondary coil acts as the output coil. Soft-iron core links magnetic flux between coils.

✅ Correct Answer Explanation

The primary coil is connected to the AC source and therefore serves as the input coil. The secondary coil delivers the transformed voltage to the external circuit and serves as the output coil. The soft-iron core provides a low-reluctance path for the alternating magnetic flux, ensuring efficient magnetic coupling between the coils. The winding arrangement may involve coils wound one over the other or placed on separate limbs of the core. Therefore: 1 → a 2 → c 3 → d 4 → b Hence, Option A is correct.

❓ Why Other Options Are Incorrect

Option B: Primary and secondary coil functions are interchanged.
Option C: Core and winding arrangement functions are incorrectly assigned.
Option D: Secondary coil and winding arrangement are mismatched.

🎯 Strategy

Used

Direct Function Matching

Application:

�� Identify the role of each transformer component and match it with its corresponding function.

Final Logic:

�� Only Option A correctly matches all four components.

🧠 Memory Trick

Primary = Input, Secondary = Output, Core = Flux Path

📚 Class XII – Physics Part I – Chapter: Alternating Current – Topic: Structure of Transformer

3 The relation between applied voltage and back emf in the primary coil
1. It is heavily dependent on high primary resistance.
2. It relies on the approximation that ep ≈ vp.
3. It dictates infinite current if resistance is zero and back emf does not equal vp.
4. Both statements 2 and 3 are valid in ideal assumptions.
Choose the correct statement:

A 1

B 2

C 3

D 1 and 4

💡 Short Explanation

In ideal transformers, back emf nearly equals applied voltage. This limits the current in the primary. Primary resistance is assumed negligible.

✅ Correct Answer Explanation

For an ideal transformer, the induced back emf in the primary nearly balances the applied voltage: ep ≈ vp This prevents excessive current from flowing. If the back emf were absent and resistance were negligible, an extremely large current would result. The standard derivation of transformer equations relies mainly on ep ≈ vp. Hence statement 2 is correct and the correct option is B.

❓ Why Other Options Are Incorrect

Statement 1: Transformer operation does not depend on high primary resistance.
Statement 3: While physically reasonable, it is not the standard assumption used directly in deriving the voltage ratio.
Statement 4: Since statement 3 is not taken as the correct statement in this context, statement 4 is incorrect.

🎯 Strategy

Used

Elimination

Application:

�� Remove statements inconsistent with ideal transformer assumptions.

Final Logic:

�� Only statement 2 directly represents the ideal transformer relation.

🧠 Memory Trick

Back emf balances input

📚 Class XII – Physics Part I – Chapter: Alternating Current – Topic: Primary Coil and Back EMF

4 The induced emf in the secondary coil is represented mathematically by:

A Ns (dΦ/dt)

B -Ns (dΦ/dt)

C -Np (dΦ/dt)

D Np (dΦ/dt)

💡 Short Explanation

�� Based on Faraday's law. �� Negative sign follows Lenz's law. �� Secondary emf depends on secondary turns.

✅ Correct Answer Explanation

According to Faraday's law of electromagnetic induction, es = − Ns (dΦ/dt) The negative sign represents Lenz's law, indicating opposition to the cause producing the emf. Since the emf is induced in the secondary coil, the number of turns involved is Ns. Hence Option B is correct.

❓ Why Other Options Are Incorrect

�� Option A → Missing the negative sign required by Lenz's law.
�� Option C → Uses primary turns instead of secondary turns.
�� Option D → Uses primary turns and lacks the negative sign.

🎯 Strategy

Used

Formula Recall / Elimination

Application:

�� Apply Faraday's law directly.

Final Logic:

�� Secondary induced emf equals −Ns(dΦ/dt).

🧠 Memory Trick

Faraday + Lenz = Minus Sign

📚 Class XII – Physics Part I – Chapter: Electromagnetic Induction – Topic: Faraday's Law

5 Choose the correct statements about turn ratio and voltage
1. Vs/Vp = Ns/Np
2. If Ns > Np, the voltage is stepped up.
3. The ratio relies on the assumption that the same flux links both coils.
4. It works perfectly for zero-frequency direct current.

A 1, 2, 3

B 2, 3, 4

C 1, 3, 4

D 1, 2, 4

💡 Short Explanation

Voltage ratio equals turn ratio. More secondary turns give higher voltage. Common flux linkage is assumed.

✅ Correct Answer Explanation

For an ideal transformer, Vs/Vp = Ns/Np If Ns > Np, the transformer is a step-up transformer. The derivation assumes that the same magnetic flux links both the primary and secondary windings. Transformer action requires changing magnetic flux and therefore does not operate with steady DC. Thus statements 1, 2 and 3 are correct, while statement 4 is incorrect. Hence Option A is correct.

❓ Why Other Options Are Incorrect

Option B: Includes statement 4, which is false.
Option C: Includes statement 4, which is false.
Option D: Includes statement 4, which is false.

🎯 Strategy

Used

Elimination

Application:

�� Reject all options containing the false statement about direct current.

Final Logic:

�� Only Option A contains all correct statements.

🧠 Memory Trick

More Turns → More Voltage

📚 Class XII – Physics Part I – Chapter: Alternating Current – Topic: Transformer Ratio

6 Consider the statements regarding ideal transformer derivation.
1. The induced back emf ep is equal to vp.
2. The secondary is an open circuit or the current taken is small.
3. The induced emf es is approximately equal to vs.
4. The primary winding requires an infinite resistance.

A 1, 3, 4

B 1, 2, 3

C 1, 2, 3, 4

D 2, 3, 4

💡 Short Explanation

Ideal derivation assumes negligible losses. Back emf balances applied voltage. Secondary terminal voltage equals induced emf approximately.

✅ Correct Answer Explanation

In deriving the ideal transformer relation: ep ≈ vp es ≈ vs The secondary current is taken as small or the secondary is considered open. Infinite primary resistance is never assumed. Instead, winding resistance is considered negligible. Hence statements 1, 2 and 3 are correct. Therefore, Option B is correct.

❓ Why Other Options Are Incorrect

Option A: Includes incorrect statement 4.
Option C: Includes incorrect statement 4.
Option D: Omits correct statement 1 and includes incorrect statement 4.

🎯 Strategy

Used

Elimination

Application:

�� Remove options containing the false infinite-resistance assumption.

Final Logic:

�� Only Option B contains all valid assumptions.

🧠 Memory Trick

Ideal = No Losses, Not Infinite Resistance

📚 Class XII – Physics Part I – Chapter: Alternating Current – Topic: Ideal Transformer Derivation

7 In a well-designed transformer, although 100% efficiency is assumed for ideal equations,
1. Actual efficiency can be more than 95%.
2. Actual efficiency is always below 50%.
3. It cannot exceed 10% due to immense flux leakage.
4. Energy is never lost in practical setups under any conditions.

A 1

B 2

C 3

D 4

💡 Short Explanation

Practical transformers are highly efficient. Losses are minimized by design. Efficiency often exceeds 95%.

✅ Correct Answer Explanation

Ideal transformers are assumed to have 100% efficiency. Real transformers suffer losses due to flux leakage, eddy currents, hysteresis, and winding resistance. However, these losses are minimized effectively through proper design, allowing practical transformer efficiencies above 95%. Hence statement 1 is correct. Therefore, Option A is correct.

❓ Why Other Options Are Incorrect

Option B: States that actual efficiency is always below 50%, which is incorrect because practical transformers commonly achieve efficiencies above 95%.
Option C: Claims efficiency cannot exceed 10% due to flux leakage. Flux leakage is small and carefully minimized in transformer design.
Option D: Assumes no energy loss occurs in practical transformers. In reality, losses due to hysteresis, eddy currents, flux leakage, and winding resistance are always present.

🎯 Strategy

Used

Elimination

Application:

�� Remove physically unrealistic statements regarding efficiency and losses.

Final Logic:

�� Only statement 1 correctly describes practical transformer performance.

🧠 Memory Trick

Transformer ≈ 95%+ Efficient

📚 Class XII – Physics Part I – Chapter: Alternating Current – Topic: Transformer Efficiency

8 If a transformer is ideal and delivers a power output of 2200 W at 440 V, what is the primary current if the input voltage is 220 V?

A 5 A

B 10 A

C 15 A

D 20 A

💡 Short Explanation

�� Input power equals output power. �� P = VI. �� Calculate input current from input power.

✅ Correct Answer Explanation

For an ideal transformer, Input Power = Output Power = 2200 W Given: Vp = 220 V Ip = P/V Ip = 2200/220 Ip = 10 A Hence Option B is correct.

❓ Why Other Options Are Incorrect

�� Option A → Gives only half the required current.
�� Option C → Larger than calculated value.
�� Option D → Double the correct value.

🎯 Strategy

Used

Substitution

Application:

�� Substitute values into P = VI.

Final Logic:

�� Ip = 2200/220 = 10 A.

🧠 Memory Trick

Power Constant in Ideal Transformer

📚 Class XII – Physics Part I – Chapter: Alternating Current – Topic: Ideal Transformer Power Relation

9 Because input power equals output power in an ideal transformer, stepping up the voltage results in a ________ current, meaning the relationship between voltage and current is ________.

A Lower, Inverse

B Higher, Inverse

C Lower, Direct

D Higher, Direct

💡 Short Explanation

�� Power remains constant. �� Voltage increase causes current decrease. �� Voltage and current are inversely related.

✅ Correct Answer Explanation

For an ideal transformer, VpIp = VsIs If voltage increases, current must decrease to maintain constant power. Thus voltage and current vary inversely. Hence Option A is correct.

❓ Why Other Options Are Incorrect

�� Option B → Current does not increase when voltage increases.
�� Option C → Relationship is not direct.
�� Option D → Both statements are incorrect.

🎯 Strategy

Used

Conceptual Elimination

Application:

�� Use power conservation.

Final Logic:

�� Higher voltage means lower current.

🧠 Memory Trick

V↑ → I↓

📚 Class XII – Physics Part I – Chapter: Alternating Current – Topic: Power in Ideal Transformer

10 The power loss in transmission lines that is reduced by stepping up the grid voltage is given by the formula:

A I² / R

B I R²

C I² R

D V² R

💡 Short Explanation

�� Transmission loss is resistive heating. �� Heat loss follows Joule's law. �� Higher voltage reduces current.

✅ Correct Answer Explanation

Power lost in transmission wires due to resistance is P = I²R By stepping up the voltage, the current required for transmitting a given power decreases. Since power loss depends on the square of current, transmission losses are greatly reduced. Hence Option C is correct.

❓ Why Other Options Are Incorrect

�� Option A → Not the expression for power loss.
�� Option B → Dimensionally incorrect.
�� Option D → Not Joule's heating formula.

🎯 Strategy

Used

Dimensional/Unit Analysis

Application:

�� Identify the standard expression for resistive power loss.

Final Logic:

�� Transmission loss = I²R.

🧠 Memory Trick

Line Loss = I²R

📚 Class XII – Physics Part I – Chapter: Alternating Current – Topic: Transmission of Electrical Energy

11 Choose the incorrect statement about step-up transformers

A Ns is greater than Np.

B Vs is greater than Vp.

C Is is less than Ip.

D Is is greater than Ip.

💡 Short Explanation

�� Step-up transformers increase voltage. �� Power is approximately conserved. �� Current decreases when voltage increases.

✅ Correct Answer Explanation

For a step-up transformer: Ns > Np Therefore, Vs > Vp Since an ideal transformer conserves power, VpIp = VsIs When voltage increases, current must decrease. Therefore the secondary current is less than the primary current. Thus statements A, B and C are correct, while statement D is incorrect.

❓ Why Other Options Are Incorrect

�� Option A → Correct because a step-up transformer has more turns in the secondary coil.
�� Option B → Correct because output voltage exceeds input voltage.
�� Option C → Correct because current decreases as voltage increases.

🎯 Strategy

Used

Elimination

Application:

�� Use the power conservation principle to eliminate inconsistent statements.

Final Logic:

�� Step-up voltage implies step-down current.

🧠 Memory Trick

Step-Up V, Step-Down I

📚 Class XII – Physics Part I – Chapter: Alternating Current – Topic: Step-Up Transformer

12 When the ratio Np / Ns is 1/2, a 220 V input at 10 A will step up to an output where

A voltage is 440 V and current is 5.0 A

B voltage is 110 V and current is 20.0 A

C voltage is 440 V and current is 20.0 A

D voltage is 110 V and current is 5.0 A

💡 Short Explanation

�� Voltage ratio equals turn ratio. �� Power remains constant. �� Increased voltage causes reduced current.

✅ Correct Answer Explanation

Given: Np/Ns = 1/2 Therefore: Vs/Vp = Ns/Np = 2 Vs = 2 × 220 = 440 V Power conservation: VpIp = VsIs 220 × 10 = 440 × Is Is = 5 A Hence Option A is correct.

❓ Why Other Options Are Incorrect

�� Option B → Represents a step-down transformer.
�� Option C → Violates conservation of power.
�� Option D → Gives incorrect voltage and current values.

🎯 Strategy

Used

Substitution

Application:

�� Apply transformer ratio and power conservation equations.

Final Logic:

�� Voltage doubles and current becomes half.

🧠 Memory Trick

Double V → Half I

📚 Class XII – Physics Part I – Chapter: Alternating Current – Topic: Ideal Transformer Calculations

13 A step-down transformer has a primary coil with 1000 turns and a secondary coil with 100 turns. If the input voltage is 2400 V, what is the secondary voltage?

A 24 V

B 120 V

C 240 V

D 24000 V

💡 Short Explanation

�� Use transformer turn ratio. �� Secondary turns are one-tenth of primary turns. �� Voltage decreases in the same ratio.

✅ Correct Answer Explanation

Using Vs/Vp = Ns/Np Vs/2400 = 100/1000 Vs = 2400 × 0.1 Vs = 240 V Hence Option C is correct.

❓ Why Other Options Are Incorrect

�� Option A → Too small; incorrect ratio application.
�� Option B → Does not satisfy the transformer equation.
�� Option D → Represents a step-up result.

🎯 Strategy

Used

Substitution

Application:

�� Direct substitution into the transformer ratio formula.

Final Logic:

�� One-tenth turns produce one-tenth voltage.

🧠 Memory Trick

Turns ↓10× ⇒ Voltage ↓10×

📚 Class XII – Physics Part I – Chapter: Alternating Current – Topic: Step-Down Transformer

14 Question:
A step-down transformer is utilized to
1. Reduce the voltage while proportionally increasing the current.
2. Increase the voltage while reducing the current.
3. Decrease both voltage and current to perfectly safe levels.
4. Change the frequency of the alternating current.
Choose correct:

A 1

B 2

C 3

D 4

💡 Short Explanation

Step-down transformers reduce voltage. Current increases correspondingly. Frequency remains unchanged.

✅ Correct Answer Explanation

A step-down transformer reduces the output voltage relative to the input voltage. Since power is approximately conserved, VpIp ≈ VsIs a reduction in voltage results in an increase in current. Transformers do not alter the frequency of AC. Therefore only statement 1 is correct.

❓ Why Other Options Are Incorrect

Option B: Describes a step-up transformer, where voltage increases and current decreases.
Option C: A step-down transformer does not necessarily decrease both voltage and current.
Option D: Transformers do not change the frequency of alternating current.

🎯 Strategy

Used

Elimination

Application:

�� Compare each option with the definition and function of a step-down transformer.

Final Logic:

�� Lower voltage and higher current characterize a step-down transformer.

🧠 Memory Trick

Step-Down V, Step-Up I

📚 Class XII – Physics Part I – Chapter: Alternating Current – Topic: Step-Down Transformer

15 To minimize flux leakage, the primary and secondary coils can be wound ________, mitigating the effect of ________ in the core.

A Separately, Solid iron

B Over one another, Air gaps

C Far apart, High permeability

D Without insulation, Eddy currents

💡 Short Explanation

�� Flux leakage occurs when flux does not link both coils. �� Coils wound closely improve coupling. �� Air gaps increase leakage.

✅ Correct Answer Explanation

Flux leakage can be minimized by winding the primary and secondary coils over one another. This arrangement ensures that a larger fraction of the magnetic flux links both coils. Air gaps interrupt magnetic coupling and contribute to flux leakage. Hence Option B is correct.

❓ Why Other Options Are Incorrect

�� Option A → Separate windings increase leakage.
�� Option C → Large separation worsens flux linkage.
�� Option D → Insulation is essential and eddy currents are unrelated to coil insulation.

🎯 Strategy

Used

Elimination

Application:

�� Select the arrangement that maximizes magnetic coupling.

Final Logic:

�� Closely wound coils reduce leakage flux.

🧠 Memory Trick

Closer Coils → Less Leakage

📚 Class XII – Physics Part I – Chapter: Alternating Current – Topic: Flux Leakage

16 Choose the correct statements about resistance in transformer windings
1. Wire used for windings has inherent resistance.
2. Energy is lost as heat due to I²R dissipation.
3. Thick wire minimizes loss in high-current, low-voltage windings.
4. Resistance heating improves the overall magnetic flux linkage.

A 1, 2, 3

B 2, 3, 4

C 1, 3, 4

D 1, 2, 4

💡 Short Explanation

Wires possess resistance. Resistance causes heating losses. Thick wires reduce resistance.

✅ Correct Answer Explanation

Transformer windings are made of conducting wire and therefore possess resistance. Current through the winding produces heat loss given by I²R. To reduce this loss, thicker wire is used in high-current windings because it lowers resistance. Resistance heating is an energy loss and does not improve magnetic flux linkage. Hence statements 1, 2 and 3 are correct. Therefore, Option A is correct.

❓ Why Other Options Are Incorrect

Option B: Includes statement 4, which is incorrect because resistance heating is a loss mechanism.
Option C: Includes statement 4, which is incorrect because resistance heating does not improve flux linkage.
Option D: Includes statement 4, which is incorrect because resistance heating reduces efficiency rather than improving transformer performance.

🎯 Strategy

Used

Elimination

Application:

�� Reject all options containing the false statement about resistance heating.

Final Logic:

�� Only Option A contains all correct statements.

🧠 Memory Trick

Thick Wire = Less I²R Loss

📚 Class XII – Physics Part I – Chapter: Alternating Current – Topic: Copper Losses in Transformers

17 Match List I with List II regarding transformer design

List I	List II
1. Alternating magnetic field	a. Induces eddy currents
2. Solid iron core	b. Prone to high eddy currents
3. Laminated core	c. Reduces eddy current losses
4. Heat generation	d. Caused by eddy currents

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

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

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

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

💡 Short Explanation

Alternating magnetic fields induce eddy currents. Solid cores encourage eddy currents. Laminations reduce eddy current losses.

✅ Correct Answer Explanation

An alternating magnetic field induces eddy currents in conducting cores. A solid iron core permits large eddy currents and hence greater losses. Laminated cores break the current paths and significantly reduce eddy current losses. The energy lost through eddy currents appears as heat. Therefore: 1 → a 2 → b 3 → c 4 → d Hence Option A is correct.

❓ Why Other Options Are Incorrect

Option B: Incorrectly matches the magnetic field, core properties, and heating effects.
Option C: Reverses the roles of solid and laminated cores.
Option D: Incorrectly associates lamination and heat generation with the wrong effects.

🎯 Strategy

Used

Option Grouping

Application:

�� Match each transformer component or phenomenon with its corresponding physical effect.

Final Logic:

�� Only Option A provides all four correct pairings.

🧠 Memory Trick

Lamination Limits Loss

📚 Class XII – Physics Part I – Chapter: Alternating Current – Topic: Eddy Current Losses

18 Question:
Choose the correct statements regarding magnetisation reversal
1. The core's magnetisation is repeatedly reversed.
2. This reversal is driven by the alternating magnetic field.
3. Expenditure of energy in the core appears as heat.
4. Magnetic materials with high hysteresis loss are strictly preferred.

A 1, 3, 4

B 1, 2, 3

C 1, 2, 3, 4

D 2, 3, 4

💡 Short Explanation

AC repeatedly reverses magnetisation. Hysteresis consumes energy. Heat is generated in the core.

✅ Correct Answer Explanation

The alternating magnetic field continuously reverses the magnetisation of the transformer core. This repeated reversal causes hysteresis loss. The energy spent in overcoming hysteresis appears as heat. Transformer cores are made from materials having low hysteresis loss, not high hysteresis loss. Therefore statements 1, 2 and 3 are correct. Hence Option B is correct.

❓ Why Other Options Are Incorrect

Option A: Includes statement 4, which is incorrect because transformer cores require low-hysteresis materials.
Option C: Includes statement 4, which is incorrect because high hysteresis loss increases energy wastage.
Option D: Omits correct statement 1 and includes incorrect statement 4.

🎯 Strategy

Used

Elimination

Application:

�� Reject options containing the false statement about high hysteresis loss.

Final Logic:

�� Transformers require low-hysteresis materials for higher efficiency.

🧠 Memory Trick

Low Hysteresis = Better Core

📚 Class XII – Physics Part I – Chapter: Alternating Current – Topic: Hysteresis Loss

19 In the large-scale transmission of electrical energy, the voltage output of the generator is stepped-up so that

A the frequency is increased to deliver energy faster

B the current is reduced and consequently the I²R loss is cut down

C the current is increased to push more power through lines

D the electrical resistance of the cables becomes negligible

💡 Short Explanation

�� High voltage transmission reduces current. �� Lower current reduces I²R losses. �� Frequency remains unchanged.

✅ Correct Answer Explanation

For a given power, P = VI Increasing transmission voltage reduces current. Since transmission loss is proportional to I²R, a lower current dramatically reduces power loss. This is why electricity is transmitted at very high voltages. Hence Option B is correct.

❓ Why Other Options Are Incorrect

�� Option A → Transformers do not change frequency.
�� Option C → Current is reduced, not increased.
�� Option D → Resistance remains essentially unchanged.

🎯 Strategy

Used

Conceptual Elimination

Application:

�� Use the transmission-loss equation.

Final Logic:

�� Higher voltage means lower current and lower I²R loss.

🧠 Memory Trick

High V → Low Loss

📚 Class XII – Physics Part I – Chapter: Alternating Current – Topic: Transmission of Electrical Energy

20 Identify the incorrect statement about the power distribution grid

A It transmits electrical energy over long distances at high voltages.

B Voltage is stepped down at area sub-stations near consumers.

C Utility poles further step down the voltage to 240 V.

D The generator output is immediately distributed to homes without stepping up.

💡 Short Explanation

�� Power is transmitted at high voltage. �� Substations reduce voltage gradually. �� Generator output is not directly supplied to homes.

✅ Correct Answer Explanation

In electrical power systems, generator output is first stepped up to very high voltages for efficient long-distance transmission. Near consumers, substations step down the voltage. Distribution transformers mounted on utility poles further reduce the voltage to household levels such as 240 V. Therefore, statement D is incorrect.

❓ Why Other Options Are Incorrect

�� Option A → Correct description of high-voltage transmission.
�� Option B → Correct description of substations.
�� Option C → Correct description of local distribution transformers.

🎯 Strategy

Used

Elimination

Application:

�� Compare each statement with the standard power distribution sequence.

Final Logic:

�� Electricity is stepped up before transmission and stepped down before use.

🧠 Memory Trick

Generate → Step-Up → Transmit → Step-Down

📚 Class XII – Physics Part I – Chapter: Alternating Current – Topic: Power Transmission and Distribution

CUET UG Physics Booster Test 2-Transformers and Energy Transmission

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