How does alternating current transfer energy?
1 Answer
Whenever there is current, electrons flow (the usual case). Electrons that move carry energy in terms of voltage. Suppose that we want to transfer energy to a resistor in a circuit,
The power (which is a good way to express energy) is
For a direct current, the math is simple. For alternating current with peak current I , the effective current becomes
Hence the Power transferred is
If you are asking about transmission of energy to households, then alternating current is needed to keep changing magnetic flux through a Gaussian surface so that electricity is continuously produced via generator and altered via transformer. Direct current is useless in power generation.