Q. If the current is halved in a coil, then the energy stored is how much times the previous value
A) $\frac{1}{2}$
B) $\frac{1}{4}$
C) 2
D) 4
Explanation
(b) $U = \frac{1}{2}Li^{2},\ i.e.,\frac{U_{2}}{U_{1}} = \left( \frac{i_{2}}{i_{1}} \right)^{2} = \left( \frac{1}{2} \right)^{2} = \frac{1}{4} \Rightarrow U_{2} = \frac{1}{4}U_{1}$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.