一个简单的物理题(in english)

问题描述:

一个简单的物理题(in english)
A heater used on a 250V mains circuit(电路) has a 5A fuse(保险丝) in its plug(插头).
which is the hightest power rating for this heater?
A 50W B 250W C 1000W D 2000W

P=UI=250*5=1250 W
1000W选择:C.