An alternating current is given by
`I = i_1 cos omegat + i_2 sin omegat`.
The rms current is given by

Options

A. `1/(sqrt(2))(i_(1)+i_(2))`
B. `1/(sqrt(2))(i_(1)+i_(2))^(2)`
C. `1/(sqrt(2))(i_(1)^(2)+i_(2)^(2))^(1//2)`
D. `1/(2)(i_(1)^(2)+i_(2)^(2))^(1//2)`

Answer

C

Explanation

`i_(r.m.s)=sqrt((i_(1)^(2)+i_(2)^(2))/2)=1/(sqrt(2))(i_(1)^(2)+i_(2)^(2))^(1//2)`