(1)当移动到最右端时时,灯正常发亮,即电压为3V,移动电阻两端电压为3V(R2电阻被短路不起作用)
滑动电阻为:
3V÷1A=3Ω
电动势为:
总电阻×电流
(r+R1+R3)×I
=(1+2+3)×1
=6V
(2)电动势÷电阻
I=U÷(r+R1)
=6V÷3Ω
=2A
(1)当移动到最右端时时,灯正常发亮,即电压为3V,移动电阻两端电压为3V(R2电阻被短路不起作用)
滑动电阻为:
3V÷1A=3Ω
电动势为:
总电阻×电流
(r+R1+R3)×I
=(1+2+3)×1
=6V
(2)电动势÷电阻
I=U÷(r+R1)
=6V÷3Ω
=2A