# What is an electric current that reverses its direction in a regular pattern?

Jun 4, 2015

Such currents are termed as alternating currents and vary sinusoidally with time.

Depending on whether the circuit is predominantly capacitative or inductive, there may be a phase difference between the voltage and the current : The current may lead or it may lag behind the voltage.
Such things are not observed in direct current circuits.

The voltage $v$ is given as,

v = v""_0Sin omegat
Where $\omega$ is the angular frequency such that $\omega = 2 \pi \nu$ and $t$ is the time. v""_0 is the peak voltage.

The current is given by,

i = i""_0Sin (omegat + phi), where $\phi$ is the phase difference, negative or positive. i""_0 is the peak current.