問題詳情
42. A long wire carries a current of 3.0 A along the axis of a long solenoid (radius = 3.0 cm, n = 900turns/m, current = 30 mA). What is the magnitude of the magnetic field at a point 2.0 cm from theaxis of the solenoid? Neglect any end effects.
(A)34 μT
(B)64 μT
(C)30 μT
(D)45 μT
(E)4.0 μT
參考答案
答案：D
難度：計算中-1
書單：沒有書單，新增