2 3 U I R L C ( ) (a) R L C = (b) ωL=ωC (c) R L C = 2
3 R L R=40Ω XL=30Ω Q=480var S ( ) (a) 866VA (b) 800VA (c) 600VA 4 4 t=0 S uC(0−)=20V uL ( )0+ =( ) (a) 0V (b) 20V (c) 40V 80 V S 40 Ω C 40 Ω 0.5 H uC C S US uL + ++ 购买考研、考博历年真题资料,请到http://www.kaoyanmiji.com |考研秘籍网 查询清单、购买下载电子版真题