A Transformer Has a Turn Ratio Ns/Np

Answer: A. 0.2 A

A transformer has a turn ratio, N_S/N_P=4. If a 200 V AC voltage is applied across its primary coil, and it carries 1 A current, find current in the circuit connected to the secondary coil if the transformer is 80% efficient.

Solution

Given that, a transformer has a turns ratio N_S/N_P=4

Primary voltage (V_P)=200 V

N_S/N_P=V_S/V_P=4

V_s=4×200=800 V

Given that, the efficiency of the transformer =V_sI_s/ V_PI_P=80%

0.8=800×I_s/200×1

I_s=160/800=0.2 A

Hence option A is the correct answer.

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