What is alternating current ? Write an expression for its instantaneous value and write the frequency of DC.

Explanation

i. An AC is that current which changes contenuously in magnitude and periodically in direction.
The value of ac at any instant
`I=Isinomegat=Isin2pigammat.`
Where `I_(0)` is the peak value of current and angular frequency `gammaomega=2pigamma=(2pi)/(T)`
ii. The frequency of direct current is zero.