Q. An $e$.m.f. $E = 4\cos{(1000t)}volt$ is applied to an LR-circuit of inductance $3\ mH$ and resistance $4\ ohms$. The amplitude of current in the circuit is
A) $\frac{4}{\sqrt{7}}A$
B) 1.0 $A$
C) $\frac{4}{7}A$
D) 0.8 $A$
Explanation
(d) $i = \frac{V}{Z} = \frac{4}{\sqrt{4^{2} + \left( 1000 \times 3 \times 10^{- 3} \right)^{2}}} = 0.8\ A$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.