Transformers: In a transformer, how many turns are necessary in a 230-V primary if the 24-V secondary has 100 turns?
A) 230
B) 240
C) 10
D) 958
E) 4

Question

Quizplus · Accepted Answer

The voltage ratio of the transformer is given by:
Vp/Vs = Np/Ns
where Vp and Vs are primary and secondary voltages respectively and Np and Ns are the number of turns in primary and secondary coils respectively. Substituting the given values, we get:
230/24 = Np/100
Np = (230/24)*100 = 958.33
Since the number of turns cannot be a decimal, the closest integer value is 958. Therefore, the answer is D.

Transformers: in a Transformer, How Many Turns Are Necessary in a 230-V