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Physics · PYQ NEET UG 2026
हिन्दीConsider a long solenoid of length $l$ and radius $r$. If $n$ is the number of turns per unit length and $\mu_0$ is the permeability of free space, the inductance of the solenoid is :
Correct answer · Option 4
$2\mu_0 \pi n^2 r^2 l$
Explanation
The inductance of a solenoid is given by $L = \mu_0 n^2 A l$, where $A = \pi r^2$ is the cross-sectional area. Thus, $L = \mu_0 \pi n^2 r^2 l$.
