某RLC串联交流电路中已知P=120W,QL=280var,QC=120var,则该电路的复功率为( )
A: [img=163x33]18031a9ad1d15e4.png[/img]
B: [img=163x33]18031a9ad9b3aaa.png[/img]
C: [img=163x33]18031a9ae2ca0c0.png[/img]
D: [img=163x33]18031a9aebece64.png[/img]
A: [img=163x33]18031a9ad1d15e4.png[/img]
B: [img=163x33]18031a9ad9b3aaa.png[/img]
C: [img=163x33]18031a9ae2ca0c0.png[/img]
D: [img=163x33]18031a9aebece64.png[/img]
举一反三
- 设X为随机变量,且E(X)= −1,Var(X)=3,则[img=136x31]1803b3be69ca3f3.png[/img] A: 18 B: 9 C: 30 D: 14
- 已知(X,Y)的联合分布律为:[img=520x161]1803e1674fcfa1e.jpg[/img]则P(X≤0, |Y|<1)等于 A: 2/9 B: 1/3 C: 5/9 D: 5/6
- 已知(X,Y)的联合分布律为:[img=520x161]1803c332db8081b.jpg[/img]则P(X≤0, |Y|1)等于 A: 2/9 B: 1/3 C: 5/9 D: 5/6
- 已知[img=163x33]17da5c92675de92.jpg[/img],则[img=112x25]17da5c92893c46c.jpg[/img] 未知类型:{'options': ['2', ' 3', ' [img=25x34]17da40b126a2b85.jpg[/img]', ' [img=12x34]17da424ffa6f2d7.jpg[/img]'], 'type': 102}
- 已知X的分布列为[img=525x34]17e0a9d4b878bef.jpg[/img]求[img=45x18]17e0a9d4c1377d8.jpg[/img]的分布列 未知类型:{'options': ['', ' [img=416x19]17e0a9d4d41b68f.jpg[/img]', ' P(X=1)=0.2,P(X=0)=0.2,P(X=4)=0.2,P(X=9)=0.5', ' 以上都不对'], 'type': 102}