Two coaxial solenoids are made by winding thin insulated wire over a pipe of cross sectional area $A=$ $10…
Two coaxial solenoids are made by winding thin insulated wire over a pipe of cross sectional area $A=$ $10 \mathrm{~cm}^2$ and length $=20 \mathrm{~cm}$. If one of the solenoids has 300 turns and the other 400 turns, their mutual inductance is $\left(\mu_0=4 \pi \times 10^{-7} \mathrm{Tm} \mathrm{A}^{-1}\right)$