Question

R.M.S value of current $i=3+4sin(\omega t+\pi /3)$ is :

• A. 5 A
• B. $\sqrt{17}A$
• C. $\frac{5}{\sqrt{2}}A$
• D. $\frac{7}{\sqrt{2}}A$

Answer 1

The correct option is B $\sqrt{17}A$

The current,

$i=3+4sin(wt+\pi /3)$ (Given)

$i^2=(3+4sin(wt+\pi /3){)}^2$

$i^2=9+16si{n}^2(wt+\pi /3)+24sin(wt+\pi /3)$

$<i^2>=9+16\left(1/2\right)+24\left(0\right)$= 17

The rms value is $\sqrt{17}$ .

The correct option is B.