Transformers: Interactive Learning Quizzes for Electrical and Electronic Principles

Question 1

A transformer has 1200 turns on its primary winding and 240 turns on its secondary winding. What is the turns ratio of this transformer?

Accepted Answer

5

Answer

24

Answer

0.2

Answer

1200

Question 2

To minimize eddy current losses in transformer cores, they are typically:

Accepted Answer

Laminated

Answer

Solid

Answer

Coated

Answer

Annealed

Question 3

The turns ratio of a transformer is directly proportional to its:

Accepted Answer

Voltage ratio

Answer

Current ratio

Answer

Power ratio

Answer

Efficiency ratio

Question 4

Which transformer type is designed to prevent electrical shock between circuits?

Accepted Answer

Isolation transformer

Answer

Autotransformer

Answer

Step-up transformer

Answer

Step-down transformer

Question 5

To correctly measure the turns ratio of a transformer, which instrument should be used?

Accepted Answer

Turns ratio meter

Answer

Voltmeter

Answer

Ammeter

Answer

Ohmmeter

Question 6

When the primary voltage of a transformer increases, what is the effect on the secondary voltage?

Accepted Answer

Increases proportionately

Answer

Decreases proportionately

Answer

Remains unchanged

Answer

Reverses polarity

Question 7

What are the primary factors that affect the energy efficiency of a transformer?

Accepted Answer

Core losses, copper losses, and stray losses

Answer

Turns ratio and core construction

Answer

Load current and power factor

Question 8

Define transformer regulation and explain its practical significance in selecting transformers for specific applications.

Accepted Answer

The percentage change in secondary voltage when the load changes, relative to the rated voltage.

Answer

The ratio of primary to secondary turns.

Answer

A measure of the power losses in the transformer.

Question 9

Define a step-up transformer and explain its functionality.

Accepted Answer

Increases voltage and decreases current

Answer

Decreases voltage and increases current

Answer

Increases both voltage and current

Answer

Decreases both voltage and current

Question 10

State the formula for calculating transformer efficiency and explain its significance.

Accepted Answer

Efficiency = Output power / Input power

Answer

Efficiency = Input power / Output power

Answer

Efficiency = Input voltage / Output voltage

Answer

Efficiency = Output current / Input current

Question 11

Explain the purpose of laminating the core of a transformer and its impact on transformer operation.

Accepted Answer

Reduces eddy current losses

Answer

Increases hysteresis losses

Answer

Improves insulation

Answer

Increases saturation current

Question 12

Identify the functions of a transformer, excluding power conversion.

Accepted Answer

Electrical isolation

Answer

Voltage conversion

Answer

Current conversion

Answer

Frequency conversion

Question 13

How do core losses affect the efficiency of a transformer?

Accepted Answer

Core losses decrease efficiency by increasing energy dissipation.

Answer

Core losses increase efficiency by reducing energy dissipation.

Answer

Core losses have no effect on efficiency.

Answer

Core losses improve efficiency by enhancing voltage regulation.

Question 14

What is the primary function of a transformer?

Accepted Answer

To transfer electrical energy from one circuit to another through electromagnetic induction

Answer

To store electrical energy only

Answer

To regulate voltage levels only

Question 15

What is the relationship between the number of turns on the primary and secondary coils of a transformer?

Accepted Answer

The turns ratio is directly proportional to the ratio of primary to secondary turns

Answer

The turns ratio is equal to the difference in turns

Answer

The turns ratio is equal to the product of turns

Question 16

What is the effect of increasing the number of turns on the secondary coil of a transformer?

Accepted Answer

Increase in output voltage and decrease in output current, while maintaining the power

Answer

No change in output voltage and decrease in output current

Answer

Increase in output voltage and increase in output current

Question 17

What is the ideal efficiency of a transformer?

Accepted Answer

100%

Answer

25%

Answer

75%

Answer

50%

Question 18

Which of the following is a factor that affects the efficiency of a transformer?

Accepted Answer

Core losses

Answer

Output voltage only

Answer

Input current only

Answer

Turns ratio only

Question 19

What is the purpose of laminating the core of a transformer?

Accepted Answer

To reduce eddy current losses

Answer

To improve magnetic permeability

Answer

To increase insulation resistance

Answer

To enhance heat dissipation

Question 20

What type of material is typically used for transformer cores?

Accepted Answer

Soft iron

Answer

Plastic

Answer

Copper

Answer

Aluminum

Question 21

What is the purpose of using an oil-filled transformer?

Accepted Answer

To provide insulation and cooling

Answer

To enhance portability

Answer

To reduce weight

Answer

To increase efficiency

Question 22

Which of the following is a common application of transformers?

Accepted Answer

Voltage conversion

Answer

Energy storage only

Answer

Circuit protection only

Answer

Current measurement only