Question

Please show all work and specify the correct answer at the bottom. Do not put down an answer that is not one of the choices.

A cylindrical insulated wire of diameter 6.0 mm is tightly wound 150 times around a cylindrical core to form a solenoid with adjacent coils touching each other. When a 0.20 A current is sent through the wire, what is the magnitude of the magnetic field on the axis of the solenoid near its center? (μ ₀ = 4π × 10^-7 T · m/A)

	5.7 × 10-5 T
	1.2 × 10-5 T
	2.1 × 10-5 T
	4.2 × 10-5 T
	9.8 × 10-5 T

Answer 1

given that

a = 0.006 m

N = 150

L = N*a = 150*.006 = 0.9 m

magnetic field on the axis of the solenoid near its center is

B = u0*N*i / L

B = 4*3.14*10^(-7)*150*0.2 / 0.9

B = 4.2*10^(-5) T

B = 4.2*10^(-5) T