The resistance of the primary coil of a well-designed, 1:10 step-down transformer is 1 $\Omega$ .With the secondary circuit open, the primary is connected to a 12 V ac generator.The primary current is:
A)essentially zero
B)about 12 A
C)about 120 A
D)depends on the actual number of turns in the primary coil
E)depends on the core material

Question

Quizplus · Accepted Answer

With the secondary circuit open, there is no load on the transformer, which means no current flows in the secondary coil. Hence, according to the transformer law, the primary current is also zero. The resistance of the primary coil does not affect the current in this case.

The Resistance of the Primary Coil of a Well-Designed, 1:10 Ω\OmegaΩ

The Resistance of the Primary Coil of a Well-Designed, 1:10 $\Omega$