An ac current is represented as
i=52+10 cos (650 πt+π6) Amp
The r.m.s. value of the current is [2025]
(3)
i=52+10 cos (650 πt+π6)
i2=50+100 cos2 (650 πt+π6)+(2)(52)(10) cos (650πt+π6)
<i2>=50+1002+0
<i2>=100
<i>=10 Amp