有一类电学题,设计新颖、巧妙,看似完全相同的两个电路,只要接入不同的电表,就会使一个电路为串联,一个电路为并联,请看下面两例. 例1 在图1电路的○里填入适当的电表符号,使图(a)中灯L1与灯L2串联,且都能发光;使图(b)中灯L1与灯L2并联,且都能发光. There is a class of electrical problems, the design of novel, ingenious, seemingly identical two circuits, as long as access to different meters, it will make a circuit in series, a circuit for parallel, see the following two examples. Example 1 In Figure 1 The circuit ○ is filled with the appropriate meter symbol, so that the lamp L1 and the lamp L2 in the diagram (a) are connected in series and can emit light; the lamp L1 and the lamp L2 in the diagram (b) can be connected in parallel, and both can emit light.