Q. When the current flowing in a circular coil is doubled and the number of turns of the coil in it is halved, the magnetic field at its centre will become
A) Four times
B) Same
C) Half
D) Double
Explanation
(b) $\frac{\mu_{0}}{4\pi}.\frac{2\pi ni}{r} \Rightarrow B \propto ni$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.