V
votinhhero


cho doan mach AM gom cuon day mac noi tiep voi doan mach MN chua tu dien Cva noi tiep voi doan NB chua bien tro R.dat vao hai dau AN hay AM mot hieu dien the u=Ucos(wt+fi).thi hai doan mach co cung he so cong suat =1/2.mac hieu dien the u tren vao 2 dau AB.thay doi R de cong suat mach dat cuc dai.bieu thuc nao sau day sai?
A.2R=(\sqrt[2]{3}-1).Zam
B.2R=(\sqrt[2]{3}-1)Zan
C.\sqrt[]2{3}R=(\sqrt[2]{3}-1)Zc
D.Zmn=\sqrt[2]{3}Zam
A.2R=(\sqrt[2]{3}-1).Zam
B.2R=(\sqrt[2]{3}-1)Zan
C.\sqrt[]2{3}R=(\sqrt[2]{3}-1)Zc
D.Zmn=\sqrt[2]{3}Zam