Physics · Oct / Nov 2021 · Paper 12 · Question 34

A transformer with an efficiency of 100% has a primary voltage input of 600 V and a secondary voltage output of 240 V. The secondary coil is attached to a resistor of resistance 120 Ω. [diagram of transformer with primary coil, secondary coil, 600 V a.c. input, 120 Ω resistor, 240 V a.c. output] What is the power dissipated in the resistor and what is the current in the primary coil?

1. Apower / W: 120, current / A: 0.20
2. Bpower / W: 120, current / A: 5.0
3. Cpower / W: 480, current / A: 0.80
4. Dpower / W: 480, current / A: 1.3

As printed in the paper