Electrical Transformer MCQ:
Of the mentioned transformers the secondary winding of which of the following transformer is always kept closed
The secondary winding of _____________ should be always kept closed:
- Power transformer
- Current transformer
- Potential transformer
Correct answer: 2. Current transformer
The secondary winding of a current transformer is always kept closed.
Explanation: Current Transformers are build to have a very small turns ratio. i.e a 1000:5 Current Transformer has turns ratio of 1/200. In such a transformer the voltage across the secondary windings would be increased tremendously. In the given scenario, it will increase by 200 times. Such high voltage developed across the open-circuited secondary circuit leads to explosion and arc as which in turn will result in severe accidents.
To avoid this all, the secondary terminal of the current transformer should always be kept open.