Question

The coefficient of self-inductance of a solenoid is `0.18 mH`. If a crude of soft iron of relative permeability `900` is inserted, then the coeffcient of self-inductance will become nearly
A. `5.4 mH`
B. `162 mH`
C. `0.006 mH`
D. `0.0002 MH`

Answer 1

Correct Answer - B
`L=muniimplies(L_(2))/(L_(1))=(mu)/(mu_(0))` (`n` and `i` are same )
`impliesL_(2)=M_(r )L_(1)=900xx0.18=162mH`