Transformers MCQs (Part-9)

What is the purpose of using harmonics in transformer analysis?

A Voltage regulation
B Assess waveform distortion
C Measure efficiency
D Calculate losses

What is the primary cause of harmonic distortion in transformers?

A Load imbalance
B High frequency
C Core saturation
D Non-linear loads

In the equivalent circuit of a transformer, what does the series impedance represent?

A Voltage regulation
B Core losses
C Leakage reactance
D Magnetizing current

How does the impedance of a transformer affect its voltage regulation?

A Affects voltage drop
B Increases efficiency
C Increases voltage
D Decreases current

What type of current is responsible for causing harmonics in transformers?

A Harmonic current
B Alternating current
C Pulsating current
D Direct current

What is the impact of harmonics on transformer efficiency?

A Increases current flow
B Increases efficiency
C No impact
D Reduces efficiency

How does the core loss of a transformer relate to its equivalent circuit?

A Represented by shunt resistance
B Represented by leakage reactance
C Represented by series reactance
D Represented by load current

What is the primary function of the magnetizing reactance in a transformer’s equivalent circuit?

A Control voltage
B Limit current
C Represent core magnetization
D Provide energy

How can harmonic currents affect the operation of a transformer?

A Increase core efficiency
B Cause overheating
C Improve voltage regulation
D Reduce impedance

What is the significance of the no-load impedance in a transformer’s equivalent circuit?

A Models transformer heating
B Represents winding resistance
C Reflects magnetizing current
D Represents load current

What is the impact of harmonics on the insulation of a transformer?

A Accelerates aging
B Enhances insulation
C No impact
D Prevents failure

How do transformers behave under non-sinusoidal waveforms due to harmonics?

A No effect
B Reduced load capacity
C Increased losses
D Increased efficiency

What does the leakage reactance in a transformer’s equivalent circuit represent?

A Energy loss
B Power transfer
C Magnetic coupling
D Voltage drop under load

How can the impedance of a transformer impact its short-circuit performance?

A Reduces short-circuit current
B Does not affect short-circuit current
C Increases voltage regulation
D Increases short-circuit current

What is the role of an impedance relay in transformer protection?

A Detect overload
B Detect fault current
C Prevent voltage surge
D Limit harmonic distortion