(1)
P=UI
I=P/U=25/220=0.114A
(2)P=w/t
W=Pt,P=25W,t=20min=1200s
=25×1200
=30000J
(3)W=Pt,P=25w=0.025kw ,t=4×30=12h
=0.025×120
=3kw·h
即3度电.
来自《中学物理导航》的解答.
(1)
P=UI
I=P/U=25/220=0.114A
(2)P=w/t
W=Pt,P=25W,t=20min=1200s
=25×1200
=30000J
(3)W=Pt,P=25w=0.025kw ,t=4×30=12h
=0.025×120
=3kw·h
即3度电.
来自《中学物理导航》的解答.