A laboratory step-down transformer is rated 220 V/11 V (rms) and may be treated as ideal. It is used to operate a heater coil of resistance 5 Ω connected across the secondary.
a. (i) Calculate the rms current in the secondary.
b. (ii) Determine the rms current in the primary and hence find the resistance that the 220 V source effectively "sees".
c. (iii) Calculate the power delivered to the heater and verify that it equals the input power drawn from the source.