如图所示,理想变压器原线圈与10V的交流电源相连,副线圈并联两个小灯泡a和b,小灯泡a的额定功率为0.3w,

2024-11-19 17:30:41
推荐回答(1个)
回答1:

因a正常发光,根据公式P a =
U 2
R
,得U a =
P a R a

副线圈电压U 2 =Ua=
P a R a
=3V,
n 1
n 2
=
U 1
U 2
=
10
3

a正常发光时,根据公式P a =U a I a 得 I a =
P a
U a
=0.1A,
因b灯与a 灯并联,则 U b =U a =3v
根据公式
I 1
I 2
=
n 2
n 1

副线圈总电流 I 2 =
n 1
n 2
I 1 =
10
3
×0.09=0.3A,
又因b灯与a 灯并联副线圈总电流 I 2 =I a +I b
故流过灯泡b的电流 I b =I 2 -I a =0.2A=
1
5
A;
故答案为:10:3;
1
5