下列说法不正确的是( )
A.伏特表的内阻一般都很大
B.伏特表使用时并联在电路中
C.为了扩大量程,应在伏特表上并联一个电阻
D.伏特表是用来测量电压的
参考答案:C
35.—Sorry for having kept you waiting .But for the traffic jam,I________20 minutes earlier.—Never mind.I haven’t been waiting that long.
A.arrived
B.would arrive
C.would have arrived
D.had arrived
在如图所示的电路中,电源电动势为E,内阻为r,当滑动变阻器的滑片向上滑动时,则( )
A.电阻消耗的电功率变大
B.电源总的功率变大
C.电源内部消耗的功率变小
D.电容器储存的电量变小