Question

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

• A. $2.4\pi \times {10}^{-5}H$
• B. $4.8\pi \times {10}^{-4}H$
• C. $4.8\pi \times {10}^{-5}H$
• D. $2.4\pi \times {10}^{-4}H$

Answer 1

The correct option is D $2.4\pi \times {10}^{-4}H$

$m=\frac{{\mu }_0{N}_1{N}_{2}A}{1}$
Substituting, $M=2.4\pi \times {10}^{-4}H$