Answer:
C. 72
Explanation:
Transformer: A transformer is an electromagnetic device that uses the property of mutual inductance to change the voltage of alternating supply.
In a ideal transformer,
Vs/Vp = Ns/Np ............................................. Equation 1
Where Vp = primary voltage, Vs = secondary voltage, Ns = Secondary turn, Np = primary turn.
Making Ns the subject of the equation,
Ns =(Vs/Vp)Np .......................................... Equation 2
Given: Vs = 24 V, Vp = 115 V, Np = 345.
Substitute into equation 2
Ns = (24/115)345
Ns = 72 turns.
Thus the number of turns in the secondary = 72 turns.
The right option is C. 72
