A solenoidal coil has 50 turns per centimetre along its length and a cross-sectional area of `4xx10^(-4)m^(2)`. 200 turns of another wire is wound round the first solenoid co-axially. The two coils are electrically insulated from each other. Calculate the mutual inductance between the two coils.

Explanation

`n_(1) = 50` turns per cm = 5000 turns per metre
`n_(2)l=200, A=4xx10^(-4)m^(2)`
`M=mu_(0)n_(1)(n_(2)l)A`
`=4 pi xx 10^(-7) xx 5000 xx 200 xx 4 xx 10^(-4) H`
`=5.03 xx 10^(-4)H`