An alternating current at any instant is given by $i = [ 6 + \sqrt { 56 } \sin ( 100 \pi t + \pi / 3 ) ]$ A. The $rms$ value of the current is $\_\_\_\_$ A.
An alternating current at any instant is given by $i = [ 6 + \sqrt { 56 } \sin ( 100 \pi t + \pi / 3 ) ]$ A. The $rms$ value of the current is $\_\_\_\_$ A.