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AP EAMCET · PHYSICS · Electromagnetic Induction

The length of a wire required to make a solenoid of length \(l\) and self-induction \(L\) is

  1. A \(\sqrt{\frac{4 \pi L l}{\mu_0}}\)
  2. B \(\sqrt{\frac{L I}{4 \pi \mu_0}}\)
  3. C \(\sqrt{\frac{2 \pi L I}{\mu_0}}\)
  4. D \(\sqrt{\frac{\mu_0 L I}{4 \pi}}\)
Verified Solution

Answer & Solution

Correct Answer

(A) \(\sqrt{\frac{4 \pi L l}{\mu_0}}\)

Step-by-step Solution

Detailed explanation

Length of wire in solenoid \(=2 \pi r \times N\) \[ =2 \pi r \sqrt{\frac{L l}{\mu_0 \pi r^2}}\left\{\begin{array}{c} \therefore L=\frac{\mu_0 N^2 A}{l} \\ A=\pi r^2 \end{array}\right\}=\sqrt{\frac{4 \pi L l}{\mu_0}} \]