Question

The CT supplies current to the current coil of a wattmeter power factor meter, energy meter and, an ammeter. These are connected as?

(a) All coils in parallel

(b) All coils in series

(c) Series-parallel connection with two in each arm

(d) Series-parallel connection with one in each arm

This question was posed to me in an interview for job.

My query is from Advanced Problems on Magnetically Coupled Circuits topic in portion Resonance & Magnetically Coupled Circuit of Network Theory

Answer 1

Right answer is (b) All coils in series

Explanation: Since the CT supplies the current to the current coil of a wattmeter, therefore the coils are connected in series so that the current remains the same. If they were connected in parallel then the voltages would have been same but the currents would not be same and thus efficiency would decrease.