变压器在运行中,绕组中电流的热效应所引起的损耗叫什么损耗?交变磁场在铁芯中引起的损耗叫什么损耗?
参考答案:第一种通常称为铜耗;第二种可分为磁滞损耗和涡流损耗,合称为铁耗。
—This new model bike _____ Uncle Wang last week.
—How beautiful! By the way, what’s it _____?[ ]
A. was made by; made of
B. was made; made from
C. was made to; make up
D. made by; made of
低压供电,负荷电流为()及以下时,宜采用直接接入式电能表。
A、40A
B、50A
C、60A
D、80A