Alternating current and energy transmission – basic principles
How it works
Alternating current (AC) is electric current whose direction and magnitude change periodically. In households, a sinusoidal alternating voltage with 230 V root mean square value and 50 Hz is usually used. Alternating current enables the efficient transport of electrical energy over large distances, since the voltage can be easily changed with transformers. For simple school examples with ohmic consumers, the electric power is calculated with P = U_eff * I_eff, where U_eff and I_eff are the root mean square values of voltage and current intensity. Transformers work with a changing magnetic field and therefore with alternating current.
Alternating current changes its direction and magnitude periodically. For energy transmission, the voltage is increased with transformers so that, at the same power, the current intensity becomes smaller and the transmission losses decrease. In simple alternating-current circuits with ohmic consumers, the following applies for power: P = U_eff * I_eff.
An example
Why is electrical energy transmitted over long distances at high voltage?
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50 Exercises
To the learning unit →Own explanation and own practice exercises by AmyMath. Subject reference framework: Physics. The topic assignment may vary by federal state.