Question

The primary coil of a transformer has 200 turns, and the secondary coil has 800 turns. The transformer is connected to a 120-volt (rms) ac source. What is the (rms) current I1 in the primary coil if the secondary coil is terminated by a 20-ohm resistor? Express your answer numerically in amperes

Answer 1

Answer:

96 A

Explanation:

Number of turns in primary that is $N_1=200$

Number of turns in primary that is $N_2=800$

Resistance connected in secondary = 20 ohm

We know that $\frac{N_1^2}{N_2^2}=\frac{Z_1}{Z_2}$

$\frac{200^2}{800^2}=\frac{Z_1}{20}$

$Z_1=1.25$

So current in primary $I=\frac{V}{Z}=\frac{120}{1.25}=96\ A$