A solenoid is wound with 970 turns on a form 4.0 cm in diameter and 50 cm long.The windings carry a current I in the sense that is shown in the figure.The current produces a magnetic field,of magnitude 4.3 mT,near the center of the solenoid.Find the current in the solenoid windings.(μ₀ = 4π × 10^-7 T • m/A) A) 1.8 A B) 1.5 A C) 1.3 A D) 2.2 A E) 2.0 A

Question

Quizplus · Accepted Answer

From the given data, we can use the formula for the magnetic field inside a solenoid:
B = μ₀nI
where B = 4.3 mT = 4.3 × 10⁻³ T, n = N/l, N = 970, l = 50 cm = 0.5 m, μ₀ = 4π × 10⁻⁷ T • m/A.

Plugging in the values and solving for I, we get:
I = B/μ₀n = (4.3 × 10⁻³)/(4π × 10⁻⁷ × 970/0.5) = 1.8 A

Therefore, the answer is choice A) 1.8 A.

A Solenoid Is Wound with 970 Turns on a Form