A certain utility transformer is designed to step up the emf from $1 \mathrm{kV}$ to $25 \mathrm{kV}$. If the primary has 1000 turns of wire, how many turns of wire does the secondary have?
A) 25,000
B) 4000
C) 2500
D) 40
E) 25
F) Some other result (specify).
$\mathrm{T}$. One needs more information to answer.

Question

Quizplus · Accepted Answer

The turns ratio of a transformer is equal to the ratio of the secondary voltage to the primary voltage. In this case, the secondary voltage is 25 kV and the primary voltage is 1 kV, so the turns ratio is 25. This means that the secondary winding has 25 times as many turns as the primary winding. Since the primary winding has 1000 turns, the secondary winding must have 25 * 1000 = 25,000 turns.

A Certain Utility Transformer Is Designed to Step Up the Emf