Current Transformer MCQ Questions with Answers
A current transformer is a type of instrumentation transformer that steps down current in power systems to safe levels that can be processed via relays and measurement devices/equipment. Current transformers can be found in generation stations and switching stations.
Given below are the most important Current Transformer MCQ Questions
Electrical Engineering MCQ
- 1 Current Transformers are used for
- 2 Secondary winding rating of Current Transformer
- 3 Secondary circuit of Current transformer should never become
- 4 Selector switches used for CT should be of which type
- 5 Primary Terminals of CT are marked using letters
- 6 Secondary Terminals of CT are marked using letters
- 7 Current transformer with rated secondary current of 5 A and Rating factor 4.0 RF can hold secondary current of
- 8 Cast Resin type Current Transformer is recommended for
- 9 Turns ratio of current transformers
- 10 What happens if the secondary of a current transformer is open-circuited
Current Transformers are used for
Current Transformers are used for:
- Measurement purposes
- Instrumentation
- Protection
- All of the above
Correct answer: 4. All of the above
A current transformer plays the measurement, instrumentation as well as protection roles in power systems.
Secondary winding rating of Current Transformer
Current transformers usually have a secondary winding rating of:
- 5 A
- 20 A
- 50 A
- 100 A
Correct answer: 1. 5 A
Secondary circuit of Current transformer should never become
Secondary circuit of Current transformer should never become:
- Open circuited
- Short circuited
- Any of these
Correct answer: 1. Open circuited
Explanation: Complete explanation for CT secondary closure
Selector switches used for CT should be of which type
Selector switches used for CT should be of which type:
- Make before break
- DPDT
- Low impedance
- None of these
Correct answer: 1. Make before break
Explanation: The selector switches used for CT should be of Make before break type so that CT never becomes open-circuited.
Primary Terminals of CT are marked using letters
Primary Terminals of CT are marked using letters:
- X1 and X2
- H1 and H2
- P1 and Q1
- P1 and U1
Correct answer: 2. H1 and H2
Secondary Terminals of CT are marked using letters
Secondary Terminals of CT are marked using letters:
- X1 and X2
- H1 and H2
- P1 and Q1
- P1 and U1
Correct answer: 1. X1 and X2
Current transformer with rated secondary current of 5 A and Rating factor 4.0 RF can hold secondary current of
Current transformer with rated secondary current of 5 A and Rating factor 4.0 RF can hold secondary current of:
- 4 A
- 5 A
- 10 A
- 20 A
Correct answer: 4. 20 A
Rating factor of CT indicates maximum current that can flow through a CT without exceeding the thermal capability of its windings
Cast Resin type Current Transformer is recommended for
Cast Resin type Current Transformer is recommended for:
- Indoor use
- Outdoor use
Correct answer: 2. Outdoor use
Generally cast resin type transformers are recommended for outdoor use.
Turns ratio of current transformers
Current transformers (CTs) have turns ratios:
- Greater than one
- Lesser than one
- Equal to one
- None of the above
Correct answer: 2. Lesser than one
Current transformers have turns ratios less than one.
What happens if the secondary of a current transformer is open-circuited
What happens if the secondary of a current transformer is open-circuited:
- A decrement in an overall efficiency of the metering circuit occurs
- Dangerously high voltages can develop
- Wrong values of output
- Nothing happens
Correct answer: 2. Dangerously high voltages can develop
If the secondary of a current transformer is open-circuited dangerously high voltages can develop. So the secondary of a current transformer should never be open circuited.
So that was all about the Current Transformer MCQ Questions.
Similar to Current Transformer MCQ:
- The pick-up current of a 100/5 transformer having a current setting of 200% will be
- The current transformers that are used to protect power transformer with star-delta connection against the earth and phase faults should be connected in which configuration
- The differential protection of delta/delta power transformers is achieved using which of the following connection of the current transformer
- The Zero-sequence current can flow from a line to the transformer bank if the windings are in