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

Options

A. `4.8pixx10^(-4)H`
B. `4.8pixx10^(-5)H`
C. `2.4pixx10^(-4)H`
D. `2.4pixx10^(-5)H`

Answer

C

Explanation

`M=mu_(0)n_(1)A N_(2) =(4pixx10^(-7))((300)/0.20)(10xx10^(-4))(400)=2.4pixx10^(-4) H`