The primary of a transformer has 100 turns and its secondary has 200 turns. If the voltage at the primary is 100V, determine the voltage at the secondary.

A. 50V
B. 100V
C. 200V
D. 400V

Correct Answer: Option C

Explanation

The ideal transformer (either step-up or step-down) works with the equation:

Vs/Vp=Ns/Np=Ip/Is
where Vs and Vp are the voltages applied to the secondary and the primary respectively

Ns and Np are the number of turns on the secondary and primary coils respectively

Ip and Is are the currents flowing in the primary and secondary coils respectively.

Vs/100=200/100

Vs=200×100/100=200V