Question

The ratio of the turns per unit length in two inductors is \[ 2:1. \] Then the ratio of the impedances produced by the inductors is

• A. \(2\)
• B. \(4\)
• C. \[ \frac{1}{2} \]
• D. \[ \frac{1}{4} \]

Hint:

For a solenoid, \[ L=\mu_0 n^2Al. \] Therefore, \[ L\propto n^2 \] and at a fixed frequency, \[ X_L=\omega L\propto n^2. \] If turns per unit length double, inductive reactance becomes four times.

Answer 1

The Correct Option is B