P额1 |
U额1 |
6W |
6V |
P额2 |
U额2 |
6W |
3V |
∵I1<I2,
∴两灯泡串联时,一灯泡正常发光,另一只较暗,正常发光的一定是L1,
∵R1=
| ||
P额1 |
(6V)2 |
6W |
| ||
P额2 |
(3V)2 |
6W |
∴U1=U额1=6V,U2=I1R2=1A×1.5Ω=1.5V,
U=U1+U2=6V+1.5V=7.5V,
(2)∵L1正常发光的,∴P1=P额1=6W,
P2=U2I1=1.5V×1A=1.5W,
(3)∵P1>P2,∴“6V 6W”较亮.
答:(1)电源电压为7.5V,(2)两灯泡消耗的实际功率分别是6W、1.5W;(3)“6V 6W”较亮.