Question

The magnetic field strength at the north pole of a 2.0-cmcm-diameter, 8-cmcm-long Alnico magnet is 0.10 TT. To produce the same field with a solenoid of the same size, carrying a current of 1.8 AA , how many turns of wire would you need

Answer 1

The number of turns of wire needed is 3536 turns.

Step-by-step explanation:

Given;

length of the wire, L = 8 cm = 0.08 m

magnetic field on the wire, B = 0.1 T

current in the wire, I = 1.8 A

The magnetic field produced by a solenoid is calculated as;

B = μ₀ n I

where;

n is the number of turns per length = N / L

μ₀ is permeability of free space = 4π x 10⁻⁷ N/A²

`B = (\mu_o N I)/(L) \\\\N = (BL)/(\mu_o I) \\\\N = (0.1 *0.08)/(4\pi*10^(-7) *1.8) \\\\N = 3536.32 \ turns`

Therefore, the number of turns of wire needed is 3536 turns.