题目

如图所示,R1为定值电阻,R2是正温度系数的金属热电阻,L为小灯泡,当温度下降时,(   )                                                                                                                            A. R1两端的电压增大              B. 电流表的示数增大     C. 小灯泡变亮                         D. 小灯泡变暗                                                                                                                                       答案:ABD
物理 试题推荐
最近更新