The frequency of an alternating current is 50 Hz. What is the minimum time taken by current to reach its peak value from rms value ?

Options

A. 0.02 s
B. `5 xx 10^(-3)` s
C. `10 xx 10^(-3)` s
D. `2.5 xx 10^(-3)` s

Answer

D

Explanation

(d): Time to reach peak value from rms value will be same as time taken to reach rms value from peak value.
`i = i_(0) cos omegat rArr (i_(0))/(sqrt2) = i_(0) cos omegat`
cos `pi/4 = cos omegat rArr pi/4 = rpiupsilont rArr t = 1/(8upsilon)`
`t = 1/(8xx50) = 2.5xx10^(-3) s`