Question

As a new electrical technician, you are designing a large solenoid to produce a uniform 0.160 {\rm T} magnetic field near the center of the solenoid. You have enough wire for 4200 circular turns. This solenoid must have a length of 1.25 {\rm m} and a diameter of 19.0 {\rm cm}.What current will you need to produce the necessary field?

Answer 1

Answer: I = 0.00383A (approx.)

Explanation:

Using the formula:

B = uni

Where B= magnetic field; 0.160mT

= 0.160 × 10^-2 m/T

n = N/L ; N= 4200 turns,

L =1.25mm = 1.25 × 10^-3m

u = 4π × 10 ^ -7.

Now since magnetic field inside a solenoid is independent of dimension B = uNI/L

I = BL/uN

= 0.00162 × 0.00125 /(4200 × 4π ×10 ^ -7)

I = 0.00384A