Consider an electrical transformer has 10 loops on its primary coil and 20 loops on its secondary coil. What is the voltage in the secondary coil if the primary coil is supplied with 120 V?

240 V

Explanation:

number of turns in primary coil, Np = 10

Number of loops in secondary coil, Ns = 20

Voltage in primary coil, Vp = 120 V

Let the voltage in secondary coil is Vs.

So, Vs / Vp = Ns / Np

Vs / 120 = 20 / 10

Vs / 120 = 2

Vs = 240 V

Thus, the voltage in secondary coil is 240 Volt.