Physics homework help?

Question

A step-down transformer (turns ratio = 1:8) is used with an electric train to reduce the voltage from the wall receptacle to a value needed to operate the train. When the train is running, the current in the secondary coil is 1.6 A. What is the current in the primary coil?
_______________A

Answer 1

Power in = power out (assuming perfect efficiency).

Power in = Vin*Iin
Power out = Vout*Iout = (Vin/1.8)*Iout