电流的大小是单位时间内通过导线某一截面的电荷量,也叫电流强度。电流强度有专门测量电流的仪器——电流表。电流表内部有一个永磁体,磁场均匀分布。当有电流通过时,磁场会对电流产生一安培力,力的作用会带动线圈使指针偏转。通过指针偏转大小来分辨通过的电流大小。 Current size is the unit of time through a wire cross-section of the amount of charge, also known as the current intensity. Current intensity has a special measure of current instruments - ammeter. Ammeter has a permanent magnet inside, the magnetic field is evenly distributed. When a current is passed, the magnetic field will produce a ampere current, the force will drive the coil to make the pointer deflection. Through the pointer deflection size to distinguish the size of the current through.