高中物理电磁感应现象演示实验过程中,需要用灵敏电流表来显示感应电流的有无和方向。但是现有实验室演示用电流表灵敏度低,电磁感应现象不明显。J0402演示电表满偏电流为±500μA,表头内阻为50Ω,因而满偏电压需要25mV,除了线圈电 High school physical electromagnetic induction phenomenon demonstration experiment process, need to use sensitive ammeter to show the presence and direction of the induction current. However, current laboratory demonstrations use ammeters with low sensitivity and no obvious electromagnetic induction. J0402 demonstrates that the full bias current of the meter is ±500μA, and the internal resistance of the meter is 50Ω, so the full bias voltage needs 25mV, except the coil