Question

在“描绘小灯泡伏安特性曲线”的实验中，同学们从实验室选择了一个标有“12V  6W”字样的灯泡，                  

实验器材如下：                                                                                                           

电流表A₁（量程300mA，内阻约为3Ω）；                                                                   

电流表A₂（量程600mA，内阻约为1Ω）；                                                                   

电压表V（量程15V，内阻约为3kΩ）；                                                                       

滑动变阻器R₁（0～5Ω，额定电流为5A）；                                                                 

滑动变阻器R₂（0～50Ω，额定电流为0.01A）；                                                      

电源E（电动势15V，内阻较小）；                                                                              

单刀单掷开关一个、导线若干．                                                                                  

                    

（1）实验器材中，电流表应该选择                                                                   ，滑动变阻器选择            ．（请选填仪表的符号）

（2）画出符合实验要求的实验电路图1．                                                                   

（3）描绘的伏安特性曲线如图2所示，若选取2个这样的灯泡并联，再与一个阻值为8Ω的定值电阻串联，接在电动势18V，内阻1Ω的电源两极，如图3所示，则每个灯泡消耗的电功率                           ．（请保留三位有效数字）             

                                                                                                                                   

Answer 1

①A₂；R₁；（2）如图所示；（3）4.42．