Answer:
20 V
Step-by-step explanation:
We can solve this problem by applying the transformer formula:
V(out) / V(in) = Ns / Np
Where V(out) = voltage at the secondary coil
V(in) = voltage at the primary coil
Ns = number of loops in the secondary coil
Np = number of loops in the primary coil
From the question:
V(out) = 60 V
Ns = 120
Np = 40
We need to find V(in)
V(in) = V(out) * Np / Ns
V(in) = (60 * 40) / 120
V(in) = 20 V
The voltage in the primary coil (primary voltage) is 20 V