What is $AC$ voltage? Write the equation for $AC$ voltage.

(N/A) $AC$ voltage is a voltage that periodically reverses its direction and changes its magnitude continuously with time.
The equation for $AC$ voltage is given by:
$v(t) = V_m \sin(\omega t + \phi)$
Where:
$v(t)$ is the instantaneous voltage at time $t$.
$V_m$ is the peak or maximum voltage (amplitude).
$\omega$ is the angular frequency,where $\omega = 2\pi f$ ($f$ is the frequency).
$t$ is the time.
$\phi$ is the phase constant.