分析、解答电路故障题的一般思路是:先分析故障原因是因为短路、断路或其它什么情况引起的,然后再判断是哪部分电路出现了短路或断路故障.通常情况下,若电路(或某一支路)中无电流,则电路(或某一支路)是断路;若电路中有电流(即通路),则电路中某部分电路发生了短路(亦称短接).例1(2014年常德市物理中考题)如图所示的电路中,闭合开关,发现灯泡L不亮,电流表无示数,电压表示数较大.若电路中只有 Analysis, answer the general problem of circuit fault problem is: first analyze the cause of the fault is due to short circuit, open circuit or other conditions caused, and then determine which part of the circuit has a short circuit or open circuit fault.Usually, if the circuit (or a A circuit), the circuit (or a branch) is open circuit; if there is current (ie circuit) in the circuit, some circuit in the circuit is short-circuited Year physics test questions) circuit shown in the figure, turn the switch and found that the bulb L is not bright, the ammeter no indication, the voltage that a few larger if the circuit only