有些计算题的电路图中只标明电表的位置,却没有标明电表的类型,这就要求同学们先确定电表类型,再进行相关的计算.解答这类题要注意以下几点: (1)电压表的内阻很大,接入电路时可视为“断路”; (2)电流表的内阻很小,接入电路时可视为“直通”; (3)在确定电表类型时,要保证各用电器的 Some circuit diagrams for calculation problems only indicate the position of the meter, but they do not indicate the type of the meter. This requires the students to determine the type of the meter first, and then perform related calculations. The following points should be noted when answering such questions: (1) Voltmeter The internal resistance is large, and it can be regarded as “open circuit” when it is connected to the circuit; (2) The internal resistance of the current meter is very small, and it can be regarded as “through” when it is connected to the circuit; (3) When determining the type of the meter, it is necessary to ensure each Electrical appliances