题目

电源和电流表的内阻都不计,则内个相同的电阻由并联改为串联,电流表的读数变化为   原来的                                                                                                              (    )       A.1/n                     B.1/2n                    C.1/n2                    D.2/n 答案:C
物理 试题推荐