ANS Given 9
I want solution
(1) Find the root mean square current of one cycle in an A.C. circuit in which instantaneous current is given by equation 1=√ 31 + 6 sin wt - 8 cos (wt ).
i=\sqrt{31}+10sin(\alpha -wt) \\i^2=31+100sin^2(\alpha -wt)+20\sqrt{31}sin(\alpha -wt) \\now \ \boxed{i_{rms}=\sqrt{\frac{\int_{0}^{T}{i^2dt}}{T}}} \\=\sqrt{31+50}=9 \ :)\ simple
PS : \alpha = \tan^{-1} \frac{4}{3}