U2 |
R |
∴电灯的电阻:
R1=
| ||
P1 |
(6V)2 |
3W |
R2=
| ||
P2 |
(6V)2 |
6W |
∵P=UI,
∴灯泡正常发光时的电流:
I1=
P1 |
U1 |
3W |
6V |
I2=
P2 |
U2 |
6W |
6V |
两灯串联,通过它们的电流相等,
额定电流小的灯L1正常发光,实际功率等于额定功率3W,
电路电流I=I1=0.5A,
∵I=
U |
R |
∴电路电压U=I(R1+R2)=0.5A×(12Ω+6Ω)=9V;
灯L1的实际功率P2′=I′2R2=(0.5A)2×6Ω=1.5W;
故答案为:9;1.5W.
U2 |
R |
| ||
P1 |
(6V)2 |
3W |
| ||
P2 |
(6V)2 |
6W |
P1 |
U1 |
3W |
6V |
P2 |
U2 |
6W |
6V |
U |
R |