Question #23191

1 Answer
Sep 23, 2016

We know
#"The current in AC at t th instant " I =I_msinomegat ....(1)#
#"where " I_m ="peak value of the current and "omega="frequency"#
#"Here " omega =50Hz=50xx2pi"rad/s"=100pi"rad/s"#
#I_(rms)=I_m/sqrt2#

We are to find out the value of t to reach #I to I_(rms)#

Inserting values in equation (1)

#I_m/sqrt2=I_msin(100pixxt)#

#=>sin(100pixxt)=1/sqrt2=sin(pi/4)#

#t=1/400s=2.5xx10^-3 s=2.5ms#