what is the self - inductance of a solenoid of length 40 cm , area of cross - section `20 cm ^(2)` and total number of turns 800 .

Options

A. `4.01xx10^(-3)H`
B. `4.9xx10^(-3)H`
C. `5.2xx10^(-3)H`
D. `6.1xx10^(-3)H`

Answer

A

Explanation

Given, `l=40cm=0.4m`
`A=20cm^(2)=20xx10^(-4)m^(2)`
`N=800,L=?`
`L=(mu_(0)N^(2)A)/(l)=(4pixx10^(-7)xx(800)^(2)xx20xx10^(-4))/(0.4)`
`=4.01xx10^(-3)H`