What device looks like a power transformer, except that its bushings are connected only with the source circuit?

• A. Shunt Reactor
• B. Power Transformer
• C. Voltage Regulator
• D. Current Transformer

Answer: (A)

The main idea is recognizing a device that resembles a transformer in appearance but is used to manage reactive power rather than to transfer energy to a load. A shunt reactor is connected across the line in parallel with the source circuit and absorbs reactive power to control voltage on the system. Its bushings connect to the source side, and the secondary does not feed a separate load—it’s essentially a large inductor placed in parallel with the line.

This is what sets it apart from the others: a true power transformer transfers energy between circuits via its primary and secondary windings; a voltage regulator is a transformer equipped with a tap changer to adjust voltage delivered to a load; a current transformer is used to provide a scaled current to relays or meters and is not operated as a parallel reactive element across the line.