A transformer has an efficiency of 80% and works at 10 V and 4 kW. If the secondary voltage is 240 V, then the current in the secondary coil is [2024]
(2)
Efficiency η=80%,Pi=4kW=4000W
VP=10V, VS=240V
For primary coil: IP=PiVP=400010=400A
η=VSISVPIP⇒80100=240IS10×400
⇒IS=13.33A