题目

在LC振荡电路中，已知电容器的电容为C，振荡电流I=Imsinωt，则此电路中线圈的自感系数L为多少?若该电路发射的电磁波在某种媒介中的波长为1 am，则电磁波在这种媒介中传播的速度多大? 答案：解析：由i=Imsinωt可知，振荡电流的周期：，即，故由λ=vT得该电磁波在介质中传播速度：.My brother and I like sports very much. We like 1.(run), playing basketball, swimming and so on. Of all the 2.(sport), we like swimming 3.(good). Swimming is really 4.(interest). 5.(连词) you swim in the pool, you look like a 6.(love) fish. Very cool. You will be happy if you can 7.(swim). If you often swim, you will be 8.(health). 9.(swim) can bring you a lot of fun. Come and swimming 10.(介词) us in the following two clubs.