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When the secondary winding of a current transformer is open-circuited with the primary winding energized.

When the secondary winding of a current transformer is open-circuited with the primary winding energized. Correct Answer All of the above

The secondary side of a current transformer should never be kept in open condition because, when kept open, there is a very high voltage found across the secondary side. This high voltage causes a high magnetizing current to build up on the secondary side which in turn causes high flux and makes the core to saturate. When the secondary winding of a current transformer is open-circuited with the primary winding energized, the large voltage may act as safety hazard for the operators and many even rupture the insulation.

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