If a transformer doubles its input voltage, what is the current in the secondary coil if the primary coil is 10 A.

20Amp

Explanation:

Using the transformer formula

Vs/Vp = Ns/Np = Ip/Is

Vs/Vp = Ip/Is

Vp is the primary voltage = input voltage

Vs is the secondary voltage = output voltage

Ip is the current in the primary coil

Is is the amount of current in the secondary coil.

If the transformer doubles its input voltage Vp, its output voltage Vs will be

decreased by 2 but the output current will be doubled

Given the input current Ip = 10A, the current in the secondary coil (output current) will be doubled i. e Is = 2 (10) = 20A