【判断题】A long and straight solenoid hasNturns, uniform cross-sectional areaA, and lengthL.Assume that the magnetic field is uniform inside the solenoid and zero outside. The solenoid is hollow. If the curren...
【单选题】交流接触器常用于远距离接通和分断( )的电路。
【单选题】交流接触器常用于远距离接通和分断( )的电路。
【单选题】交流接触器常用于远距离接通和分断()的电路。
【判断题】for语句中的三个表达式和两个分号都是可选项,根据需要可以省略。
【单选题】A solenoid is 3.0 cm long and has a radius of 0.50 cm. It is wrapped with 500 turns of wire carrying a current of 2.0A. The magnetic field at the center of the solenoid is:
【单选题】A small planar loop is placed inside a straight solenoid. When the angle between the normal direction of the loop and the axis of the solenoid is gradually increased from 0to 90 degree, how does the m...
D.
Decreases first and then increases.
【单选题】交流接触器常用于远距离接通和分断( )的电路。