The equation of alternating of alternating current for a cuicuit is given by `I = 50 cos 100 pi t`. Calculate
(i) frequency of a.c. applied,
(ii) virtual value of current,
(iii) value of current `1//600` s after it was maximum

Explanation

Here, `I = 50 cos 100 pi t`
Compare it with the standard form
`I = I_(0) cos omega t`, we get `I_(0) = 50 A`
`omega = 2 pi, v = (100 pi)/(2 pi) = 50 c//s`
Virtual value of current, `I_(v) = (1)/(sqrt2) = (50)/(sqrt2)`
At `t = 0, I = 50 cos 0 = 50 A = max`.
At `t = (1)/(600) s`
`I = 50 cos 100 pi xx (1)/(600) = 50 "cos" (pi)/(6)`
`= 50 cos 30^(@) = (50sqrt3)/(2) = 25sqrt3 A`