Two coaxial solenoids are made by winding thin insulated wire over a pipe of cross-sectional area A = 10cm2 and length = 20cm. If one of the solenoids has 300 turns and the other 400 turns, their mutual inductance is (μ0 = 4p × 10–7 T mA–1 )
(a) 2.4π × 10–4H
(b) 2.4π × 10–5H
(c) 4.8π × 10–4H
(d) 4.8π × 10-5H.
