A step-down transformer that operating from a 50Hz mains supply of 220 Volt rms, is used to give a decrease voltage to a secondary power supply. The final delivers 400 Watt of power to a load consisting of an equivalent resistance of 10?. The transformer should have a total of 12,500 turns. Find out:
a. The secondary voltage needed within the transformer,
b. The number of turns needed on all winding of the transformers,
c. The current that should be supplied to the transformer through the mains supply.