Q. A coil is wound on a core of rectangular cross-section. If all the linear dimensions of core are increased by a factor 2 and number of turns per unit length of coil remains same, the self-inductance increases by a factor of
A) 16
B) 8
C) 4
D) 2
Explanation
(b) As $L = \ \frac{\mu_{0}N^{2}\ A}{l}$
$\therefore\ A\ \rightarrow \ \frac{2 \times 2 \times 4}{2}$ times = 8 times
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.