The peak value of alternating current is 5A and its frequency is 60Hz. Find its rms value. How long will the current take to reach the peak starting from zero?

Explanation

(a) Here , `I_0 = 5A`
` rArr I_(rms) = (I_0)/(sqrt2) = (5A)/(sqrt2) = 3.54 A`
(b) As is evident from the graph, starting from 0, the current takes a time `T/4` to reach the peak value.
Here `T = (2pi)/(v) = ((2pi)/(60)) = ((pi)/(30))s `
The required time t` = T/4`
or `t = ((pi)/(30 xx 4) ) = ((pi)/(120))s `