| U2 |
| P |
| (220V)2 |
| 200W |
灯泡2的电阻为:R2=
| U′2 |
| P′ |
| (220V)2 |
| 40W |
两灯泡串联,R=R1+R2=242Ω+1210Ω=1452Ω
电路中的电流为:I=
| U |
| R |
| 380V |
| 1452Ω |
灯泡1两端的电压为:U1=IR1=0.26A×242Ω≈63V
灯泡2两端的电压为:U2=U-U1=380V-63V≈317V
灯泡2两端的电压远大于它的额定电压220V,所以将会烧坏的是灯泡2.
故答案为:“220V 40W”.
| U2 |
| P |
| (220V)2 |
| 200W |
| U′2 |
| P′ |
| (220V)2 |
| 40W |
| U |
| R |
| 380V |
| 1452Ω |