将标有“6V 3W”的L1和“6V 9W”的L2两盏灯串联在电路中,并使其中一盏灯正常发光,则应该让哪一只灯正常

2025-12-18 03:54:18
推荐回答(1个)
回答1:

L1的额定电流:I1=

P1
U1
=
3W
6V
=0.5A,R1=
U
P1
=
(6V)2
3W
=12Ω;
L2的额定电流:I2=
P2
U2
=
9W
6V
=1.5A,R2=
U
P2
=
(6V)2
9W
=4Ω;
比较可知:I1<I2
∵在串联电路中,电流处处相等,
∴此时电路中的电流应是I1,即L1正常发光,否则,会损坏L1
电路两端的总电压为:U=I1(R1+R2)=0.5A×(12Ω+4Ω)=8V.
答:应该让灯L1正常发光,此时加在电路两端的总电压是8V.