(1)∵P=UI,
∴灯泡正常发光时的电流I额=
=PL额 UL额
=1A;6W 6V
(2)灯泡正常发光时,滑动变阻器两端的电压U滑=U-UL额=9V-6V=3V,
此时滑动变阻器接入电路的阻值R滑=
=U滑 I额
=3Ω;3V 1A
(3)灯泡的电阻RL=
=UL额 I额
=6Ω,6V 1A
当滑片置于最右端时:UL=2V,
此时滑动变阻器的电压U滑′=U-UL′=9V-2V=7V,
此时电路电流:I=IL=
=UL RL
=2V 6Ω
A,1 3
滑动变阻器的最大阻值R=
=
U滑′ I
=21Ω;7V
A1 3
答:(1)灯泡正常发光时电流表的示数1A.
(2)灯泡正常发光时滑动变阻器连入电路的阻值是3Ω.
(3)滑动变阻器的最大阻值是21Ω.