The resistance of the primary coil of a well-designed, 1 : 10 step-down transformer is 1 Ω. 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
