A step-down transformer in a workshop kiln has a primary coil of 800 turns and a secondary coil of 160 turns. The primary coil is connected to an alternating current (a.c.) mains supply with a root-mean-square (rms) voltage of 240 V. The secondary coil is connected to a heating element with a resistance of 6.4 Ω.
Assuming the transformer is 100% efficient, what is the peak power dissipated in the heating element?
360 W360\text{ W}360 W
510 W510\text{ W}510 W
720 W720\text{ W}720 W
1440 W1440\text{ W}1440 W