Two coaxial solenoids are made by winding thin insulated wire over a pipe of cross-sectional area A=10 ~cm^ 2 and length =20 ~cm . If one of the solenoid has 300 turns and the other 400 turns, their mutual inductance is

Correct answer: D. 2.4 π × 10^ -4 H aligned M &= μ_ 0 N_ 1 N_ 2 A &= 4 π × 10^ -7 × 300 × 400 × 100 × 10^ -4 0.2 &=2.4 π × 10^ -4 H aligned #

BITSAT 2013

BITSAT 2013 · Physics · Electromagnetic Induction

Two coaxial solenoids are made by winding thin insulated wire over...

Two coaxial solenoids are made by winding thin insulated wire over a pipe of cross-sectional area

\mathrm{A}=10 \mathrm{~cm}^{2}

and length

=20 \mathrm{~cm} .

If one of the solenoid has 300 turns and the other 400 turns, their mutual inductance is

\left(\mu_{0}=4 \pi \times 10^{-7} \mathrm{TmA}^{-1}\right)

D. $2.4 \pi \times 10^{-4} \mathrm{H}$

\begin{aligned} M &=\frac{\mu_{0} \mathrm{ N}_{1} \mathrm{ N}_{2} \mathrm{ A}}{\ell} \\ &=\frac{4 \pi \times 10^{-7} \times 300 \times 400 \times 100 \times 10^{-4}}{0.2} \\ &=2.4 \pi \times 10^{-4} \mathrm{H} \end{aligned}