Question

The permeability of the material of the core used in a solenoid of length 1.4 m, radius 7 cm having $10^3$ turns and a self-inductance of 2.2 H is

• A. $1 \times 10^{-4}\,Hm^{-1}$
• B. $2 \times 10^{-4}\,Hm^{-1}$
• C. $3 \times 10^{-4}\,Hm^{-1}$
• D. $4 \times 10^{-4}\,Hm^{-1}$

Hint:

For a solenoid, \[ L=\frac{\mu N^2A}{l} \] Always remember that inductance increases with permeability and square of the number of turns.

Answer 1

The Correct Option is B