1. The working principle of a transformer is based on:
A. Ohm’s Law
B. Faraday’s Law of Electromagnetic Induction
C. Lenz’s Law
D. Coulomb’s Law
Answer: B. Faraday’s Law of Electromagnetic Induction
2. A transformer operates on:
A. Direct current
B. Alternating current
C. Both AC and DC
D. Static electricity
Answer: B. Alternating current
3. The core of a transformer is made of:
A. Copper
B. Aluminum
C. Silicon steel
D. Plastic
Answer: C. Silicon steel
4. What is the main purpose of the core in a transformer?
A. To increase resistance
B. To provide insulation
C. To reduce energy losses
D. To provide a path for magnetic flux
Answer: D. To provide a path for magnetic flux
5. In an ideal transformer, the input power is equal to:
A. The output power
B. Twice the output power
C. Half the output power
D. Zero
Answer: A. The output power
Types of Transformers
6. A step-up transformer:
A. Decreases voltage and increases current
B. Increases voltage and decreases current
C. Increases both voltage and current
D. Decreases both voltage and current
Answer: B. Increases voltage and decreases current
7. Which type of transformer is used in transmission lines?
A. Isolation transformer
B. Step-up transformer
C. Step-down transformer
D. Auto-transformer
Answer: B. Step-up transformer
8. An auto-transformer differs from a regular transformer because it:
A. Has multiple windings
B. Shares a single winding for input and output
C. Only steps up voltage
D. Only steps down voltage
Answer: B. Shares a single winding for input and output
9. Isolation transformers are used for:
A. Increasing efficiency
B. Voltage stabilization
C. Electrical isolation between circuits
D. Current amplification
Answer: C. Electrical isolation between circuits
10. Distribution transformers are designed for:
A. High voltage and low current
B. Low voltage and high current
C. High frequency
D. Low efficiency
Answer: B. Low voltage and high current
11. Which of the following is NOT an application of transformers?
A. Power transmission
B. Voltage regulation
C. Signal amplification
D. Electrical isolation
Answer: C. Signal amplification
12. Transformers are commonly used in power systems to:
A. Stabilize DC voltages
B. Transfer electrical energy at different voltage levels
C. Rectify AC to DC
D. Act as storage devices
Answer: B. Transfer electrical energy at different voltage levels
13. Which type of transformer is used in electrical appliances for safety?
A. Step-up transformer
B. Auto-transformer
C. Isolation transformer
D. Distribution transformer
Answer: C. Isolation transformer
14. In electronic circuits, transformers are used for:
A. Impedance matching
B. AC voltage transformation
C. Signal coupling
D. All of the above
Answer: D. All of the above
15. The main purpose of a step-down transformer in power supply is to:
A. Convert DC to AC
B. Reduce high transmission voltages to usable levels
C. Increase current
D. Generate magnetic flux
Answer: B. Reduce high transmission voltages to usable levels