Question

The ratio of coils of wire in the primary winding to the secondary winding of a transformer is 3:2. How does the transformer change the voltage of a current applied to the primary winding?

It increases to three-halves times the original.
It decreases to two-thirds the original.
It increases to three times the original.
It decreases to one-third the original

Answer 1

It decreases to two-thirds the original.

Reason: For an ideal transformer Vp/Vs = Np/Ns, so Vs = Vp*(Ns/Np) = Vp*(2/3).