解题思路:
家用电能表的单位是
kw
⋅
h
,表盘上的示数最后一位是小数十分位。电能表两次读取的示数差即为相应时间内消耗的电能。小华家在这段时间内消耗的电能为
2139.4
kW
⋅
h
−
2138.2
kW
⋅
h
=
"
1.2
"
k
W
⋅
h
,该用电器的实际功率是
。
1.2 400
<>
解题思路:
家用电能表的单位是
kw
⋅
h
,表盘上的示数最后一位是小数十分位。电能表两次读取的示数差即为相应时间内消耗的电能。小华家在这段时间内消耗的电能为
2139.4
kW
⋅
h
−
2138.2
kW
⋅
h
=
"
1.2
"
k
W
⋅
h
,该用电器的实际功率是
。
1.2 400
<>