Electrical Transformers: Interactive Learning Quizzes for Physics II

Question 1

What is the primary function of an electrical transformer?

Accepted Answer

To regulate voltage

Answer

To isolate circuits

Answer

To convert AC to DC

Answer

To protect against overcurrents

Question 2

In an ideal transformer, the turns ratio is directly proportional to:

Accepted Answer

Primary voltage / Secondary voltage

Answer

Secondary voltage / Primary voltage

Answer

Primary current / Secondary current

Answer

Secondary current / Primary current

Question 3

The laminations in the core of a transformer are used to:

Accepted Answer

Reduce eddy currents

Answer

Increase core permeability

Answer

Improve insulation

Answer

Enhance mechanical strength

Question 4

The cooling system in a transformer primarily serves to:

Accepted Answer

Prevent overheating

Answer

Enhance insulation life

Answer

Reduce noise

Answer

Improve efficiency

Question 5

In an ideal transformer, the relationship between the input and output power is:

Accepted Answer

Input power = Output power

Answer

Input power > Output power

Answer

Input power < Output power

Answer

Output power = 2 * Input power

Question 6

What is the underlying principle that enables energy transfer in transformers?

Accepted Answer

Electromagnetic induction

Answer

Direct electrical conduction

Answer

Static electricity

Answer

Mechanical energy conversion

Question 7

What is the fundamental purpose of an electrical transformer?

Accepted Answer

Altering the voltage level of an AC signal

Answer

Modifying the frequency of an AC signal

Answer

Adjusting the power of an AC signal

Answer

Shifting the phase of an AC signal

Question 8

In an ideal transformer, the ratio of the number of turns on the primary winding to the number of turns on the secondary winding is known as the:

Accepted Answer

Turns ratio

Answer

Voltage ratio

Answer

Current ratio

Answer

Power ratio

Question 9

The laminated core in a transformer primarily serves to:

Accepted Answer

Reduce eddy currents and energy dissipation

Answer

Minimize hysteresis losses

Answer

Enhance magnetic flux density

Answer

Improve insulation properties

Question 10

Autotransformers find their primary application in:

Accepted Answer

Voltage regulation applications

Answer

Power distribution networks

Answer

Electrical isolation systems

Answer

Current limiting devices

Question 11

Increasing the primary voltage in a transformer typically results in:

Accepted Answer

Increased secondary voltage and current

Answer

Decreased secondary voltage and current

Answer

Only an increase in secondary voltage

Answer

Only a decrease in secondary voltage

Question 12

Which winding configuration is known for providing the greatest level of voltage isolation?

Accepted Answer

Concentric windings

Answer

Layer windings

Answer

Helical windings

Answer

Disk windings

Question 13

The primary purpose of a cooling system in a transformer is to:

Accepted Answer

Dissipate heat generated by losses

Answer

Improve insulation characteristics

Answer

Reduce operational noise levels

Answer

Enhance energy efficiency

Question 14

Which of the following is NOT a type of electrical transformer typically used in power systems?

Accepted Answer

Rectifier

Answer

Core-type

Answer

Shell-type

Answer

Autotransformer

Question 15

What is the primary function of an ideal transformer?

Accepted Answer

To change the voltage level of an alternating current (AC) signal while maintaining power

Answer

To isolate circuits from each other

Answer

To convert AC to direct current (DC)

Answer

To regulate voltage

Question 16

The turns ratio of a transformer is defined as the ratio of:

Accepted Answer

Primary turns to secondary turns

Answer

Primary voltage to secondary voltage

Answer

Primary current to secondary current

Answer

Secondary turns to primary turns

Question 17

Which material is commonly used to construct transformer cores due to its magnetic properties?

Accepted Answer

Silicon steel

Answer

Iron

Answer

Copper

Answer

Aluminum

Question 18

The purpose of laminating transformer cores is primarily to:

Accepted Answer

Reduce eddy currents and energy losses

Answer

Enhance magnetic coupling

Answer

Increase mechanical strength

Answer

Improve heat dissipation

Question 19

The efficiency of a well-designed transformer typically ranges between:

Accepted Answer

Around 70-90%

Answer

Below 50%

Answer

Above 95%

Answer

Depends solely on the transformer size

Question 20

Which of the following is NOT a primary function of an electrical transformer?

Accepted Answer

Current conversion

Answer

Voltage conversion

Answer

Isolation

Answer

Impedance matching

Question 21

Which type of transformer is specifically designed for isolation purposes?

Accepted Answer

Isolation transformer

Answer

Autotransformer

Answer

Distribution transformer

Answer

Power transformer

Question 22

The reactance of a transformer winding is primarily caused by the:

Accepted Answer

Inductance of the winding

Answer

Magnetic field around the winding

Answer

Resistance of the winding

Answer

Capacitance of the winding

Question 23

An autotransformer is characterized by having:

Accepted Answer

Two windings with a common portion

Answer

Only one winding

Answer

Three windings

Answer

Two windings that are electrically isolated

Question 24

The core of a transformer is typically constructed from:

Accepted Answer

Laminated steel

Answer

Solid iron

Answer

Copper

Answer

Aluminum

Question 25

Which of the following is NOT a primary function of an electrical transformer?

Accepted Answer

Power conversion

Answer

Voltage transformation

Answer

Current transformation

Answer

Isolation

Question 26

The turns ratio of a transformer is defined as the ratio of:

Accepted Answer

Primary turns to secondary turns

Answer

Primary voltage to secondary voltage

Answer

Primary current to secondary current

Answer

Secondary voltage to primary voltage

Question 27

Typically, the efficiency of a transformer falls within which range?

Accepted Answer

Between 80% and 95%

Answer

Less than 50%

Answer

Between 50% and 80%

Answer

Greater than 95%

Question 28

The purpose of a transformer with multiple secondary windings is to:

Accepted Answer

Provide multiple voltage levels

Answer

Provide isolation between circuits

Answer

Step up or step down voltages

Answer

Regulate voltage

Question 29

Which of the following factors has **no** impact on the efficiency of a transformer?

Accepted Answer

Transformer size

Answer

Copper losses

Answer

Iron losses

Answer

Load factor

Question 30

Identify the type of transformer NOT included in the following list:

Accepted Answer

Potential transformer

Answer

Step-up transformer

Answer

Step-down transformer

Answer

Isolation transformer

Question 31

Which definition accurately describes the turns ratio of a transformer?

Accepted Answer

Ratio of primary turns to secondary turns

Answer

Ratio of primary current to secondary current

Answer

Ratio of secondary voltage to primary voltage

Answer

Ratio of secondary turns to primary turns

Question 32

What formula represents the efficiency of a transformer?

Accepted Answer

Output power divided by input power

Answer

Input power divided by output power

Answer

Primary power divided by secondary power

Answer

Secondary power divided by primary power

Question 33

What is the key difference between an ideal transformer and a real-world transformer?

Accepted Answer

Ideal transformers have no energy losses, while real transformers do.

Answer

Ideal transformers have a fixed turns ratio, while real transformers can have varying ratios.

Answer

Ideal transformers are used for high-voltage applications, while real transformers are used for low-voltage applications.

Question 34

Which of the following is NOT a primary function of a transformer?

Accepted Answer

Amplification of voltage and current

Answer

Isolation of circuits

Answer

Voltage transformation

Answer

Power transfer

Question 35

The transformer's core is typically made of:

Accepted Answer

Laminated steel

Answer

Copper

Answer

Solid iron

Answer

Aluminum

Question 36

The primary purpose of a transformer's turns ratio is to:

Accepted Answer

Determine the voltage transformation

Answer

Determine the power transformation

Answer

Determine the current transformation

Answer

Determine the efficiency

Question 37

In a step-up transformer, the voltage on the secondary side is:

Accepted Answer

Higher than the voltage on the primary side

Answer

Inversely proportional to the voltage on the primary side

Answer

Equal to the voltage on the primary side

Answer

Lower than the voltage on the primary side

Question 38

The efficiency of a transformer is primarily influenced by:

Accepted Answer

Core losses and copper losses

Answer

Load current

Answer

Turns ratio

Answer

Input power

Question 39

Which type of transformer is commonly used for electrical power distribution?

Accepted Answer

Distribution transformer

Answer

Autotransformer

Answer

Instrument transformer

Answer

Isolation transformer

Question 40

The equivalent circuit of a transformer typically includes:

Accepted Answer

An ideal transformer with series impedances

Answer

A series inductor and a parallel capacitor

Answer

An ideal transformer with parallel impedances

Question 41

Which of the following is considered a load for a transformer?

Accepted Answer

An electrical device connected to the secondary winding

Answer

The core

Answer

The primary winding

Question 42

An ideal transformer has 100 turns on its primary winding and 500 turns on its secondary winding. If the primary voltage is 120 V, what is the secondary voltage?

Accepted Answer

600 V

Answer

240 V

Answer

30 V

Question 43

Which of the following characteristics is NOT associated with an ideal transformer?

Accepted Answer

It can change the frequency of the input voltage.

Answer

It has zero losses.

Answer

It has infinite permeability.

Answer

It has no leakage flux.

Question 44

Which core material is commonly used in high-frequency transformers?

Accepted Answer

Ferrite

Answer

Silicon steel

Answer

Iron

Answer

Aluminum

Question 45

Which of the following is NOT a common application of transformers?

Accepted Answer

Converting DC voltage levels

Answer

Stepping up or down voltage levels in power transmission

Answer

Isolating circuits for safety purposes

Answer

Impedance matching in audio circuits

Question 46

What happens to the current in the secondary winding of a step-down transformer when the load on the secondary winding increases?

Accepted Answer

It increases

Answer

It remains the same

Answer

It decreases

Answer

It becomes zero

Question 47

Which of the following best describes the function of a transformer core?

Accepted Answer

To provide a low reluctance path for magnetic flux

Answer

To increase the resistance of the windings

Answer

To dissipate heat generated in the windings

Question 48

What type of transformer connection is used to convert a three-phase supply to a two-phase supply?

Accepted Answer

Scott-T connection

Answer

Delta-delta connection

Answer

Wye-wye connection

Answer

Open-delta connection

Question 49

What is a significant disadvantage of autotransformers compared to isolation transformers?

Accepted Answer

Lack of electrical isolation between primary and secondary windings

Answer

Larger size and weight

Answer

Lower efficiency

Question 50

What is the purpose of laminations in a transformer core?

Accepted Answer

To reduce eddy current losses

Answer

To increase the magnetic flux density

Answer

To improve insulation between windings

Answer

To provide mechanical strength