An air cored coil has a self inductance 0.1 H . A soft iron core of relative permeability 1000 is introduced and the number of turns is reduced ( 1 10 )^ th . The value of self inductance is

Step-by-step solution

For air core coil, L=0.1= ₀ ~N ^2 ~A l For soft iron core coil, L ^ = ₀ _ r ( N ^ )^2 ~A l aligned & L^ L = 1000 ₀ ( N 10 )^2 ~A l ₀ ~N ₂ ~A l & ~L ^ L ^ =10 & ~L ^ =0.1 10=1 H aligned