Xét một solenoid có chiều dài rất lớn so với bề ngang. Trong số các cách dưới đây thì cách nào là hiệu quả nhất để tăng từ trường bên trong solenoid?

Hen a gfci receptacle device is installed on a 20-ampere branch circuit (12 awg copper), what is the minimum volume allowance (in cubic inches) required for conductor fill for each conductor in the outlet box?

Which lists the pairs of plates in order from least to greatest in terms of the work done to move the electron?

When the displacement of a mass on a spring is 12a the half of the amplitude, what fraction of the mechanical energy is kinetic energy? at what displacement, as a fraction of a, is the mechanical energy half kinetic and half potential?