Question

A direct current of $5A$ is superimposed on an alternating current $I=10\sin \omega t$ flowing through a wire. The effective value of the resulting current will be

• A. $\left(15/2\right)A$
• B. $5\sqrt{3}A$
• C. $5\sqrt{5}A$
• D. $15A$

Answer 1

Answer: (B)

$5\sqrt{3}A$

effective value of dc current =$5A$
effective value of ac current=$10/\sqrt{2}A$
effective value of resulting current = $\sqrt{I_{dc}^2+I_{ac}^2}=\sqrt{5^2+{100}^2/2}=5\sqrt{3}A$