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Instrument Transformers MCQs

Practice Instrument Transformers MCQs with four options, answers and explanations for focused Electronics & Telecommunication Engineering revision.

Question 1
Measurements & InstrumentationInstrument Transformers

A current transformer is primarily used to?

  • AScale large AC current to a smaller measurable current
  • BIncrease DC voltage
  • CMeasure temperature
  • DGenerate radio frequency
Report an error
Correct Answer: A. Scale large AC current to a smaller measurable current
Explanation: A CT reproduces a scaled version of primary AC current for metering and protection.
Reference: Standard measurements and instrumentation: instrument transformers
Question 2
Measurements & InstrumentationInstrument Transformers

The secondary of an energized current transformer should generally not be?

  • AOpen-circuited
  • BConnected to its rated burden
  • CShorted through an ammeter of low impedance
  • DGrounded at one designated point where required
Report an error
Correct Answer: A. Open-circuited
Explanation: Opening an energized CT secondary can produce dangerously high secondary voltage and excessive core flux.
Reference: Standard measurements and instrumentation: instrument transformers
Question 3
Measurements & InstrumentationInstrument Transformers

A potential transformer is used mainly to?

  • AStep down high AC voltage for measurement and protection
  • BMeasure only resistance
  • CConvert DC current to AC
  • DIncrease current for welding
Report an error
Correct Answer: A. Step down high AC voltage for measurement and protection
Explanation: A PT/VT provides an accurately scaled lower voltage for instruments and protective relays.
Reference: Standard measurements and instrumentation: instrument transformers