Correct option is D
In a current transformer (CT), the secondary winding is always kept closed when the primary winding is energized. This is because an open secondary winding would lead to a dangerously high voltage, which could damage the transformer and pose a safety hazard.
Why is the secondary winding kept closed in a CT?
· A CT operates with a constant primary current.
· If the secondary is left open, no current flows, and the transformer tries to maintain the magnetic flux, resulting in an extremely high voltage across the secondary terminals.
· This can damage insulation and pose electrical hazards to personnel.
