# physics

posted by
**mitch**
.

1. x-ray machine operates at 200 kv with a current of 10 mA. The power mus be produced by a transformer which raises the voltage from 220 volts to 200 kilovolts. The power going into and out of the transformer is the same. How much current must flow in the 220 volt line to operate the x-ray machine??

having problem understanding this problem, need help setting up problem.

The power of the machine, in terms of the transformer output voltage and current, is 200*10^3 V x 10^-2 A = 4000 Watts.

The same power flows in the transformer primary, as

4000 W = 220 V x I (amps)

Solve for I