Question

Starting from the expression for the energy$W={1}/{2} \ LI^{2}$, stored in a solenoid of self-inductance L to build up the current I, obtain the expression for the magnetic energy in terms of the magnetic field B, area A and length l of the solenoid having n number of turns per unit length. Hence, show that the energy density is given by $\frac{B^{2}}{2\mu_{0}}$.

Answer 1

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