A coiled telephone cord forms a spiral with 52.0 turns, a diameter of 1.30 cm, and an unstretched length of 57.5 cm. Determine the inductance of one conductor in the unstretched cord.

The inductance of one conductor in the unstretched cord is 0.7849 μH

Explanation:

Given;

number of turns of the coil, N = 52 turns

diameter of the coil, d = 1.30 cm

radius of the coil, r = d/2 = 1.30 cm / 2 = 0.65 cm = 0.0065 m

length of the unstretched cord, l = 57.5 cm = 0.575 m

The inductance of one conductor in the unstretched cord is given by;

where;

μ₀ is permeability of free space = 4π x 10⁻⁷ m/A

A is area of coil, = πr² = π x (0.0065)² = 1.328 x 10⁻⁴ m²

L = 0.7849 μH

Therefore, the inductance of one conductor in the unstretched cord is 0.7849 μH

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