Q. Two concentric circular lops of radii $R$ and $2R$ carry currents of $2I$ and $I$ respectively in opposite sense (i.e., clockwise in one coil and counter-clockwise in the other coil). The resultant magnetic field at their common centre is
A) $\mu_{0}\frac{I}{4R}$
B) $\mu_{0}\frac{5I}{4R}$
C) $\mu_{0}\frac{3I}{4R}$
D) $\mu_{0}\frac{I}{2R}$
Explanation
The correct answer is Option C: $\mu_{0}\frac{3I}{4R}$.
A detailed explanation for this question is being prepared.
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.