(1)由U=E-Ir=-Ir+E,可知U-I图象的斜率与纵轴截距的物理意义,则新电池:
=1.5V,
E
=
r
Ω=0.3Ω;1.5?0 5
同理旧电池:
=1.2V,
E
=
r
Ω=4.0Ω.1.2?0 0.3
(2)小灯泡电阻为R=
=4.5Ω,由闭合电路欧姆定律可得:
U
P
I=
=
E
+E
r
+R
+r
A=0.31A,1.5+1.2 0.3+4.0+4.5
旧电池提供的电功率为:
=I
P
=0.31×1.2W=0.37W
E
旧电池本身消耗的电功率为:
=
P
=
r
I
W=0.38W.
0.31×0.31×4.0
故答案为:(1)1.5,0.3,1.2,4.0
(2)0.37W,0.38W