已知两个用电器的电阻分别是R<sub>1</sub>=18Ω,R<sub>2</sub>=6Ω。求把它们串联起来接在电路中,在相同的时间里()放出的热量多。
[]
[]
A、如图所示为电桥电路,已知R<sub>1sub>=1Ω、R<sub>2sub>=2Ω、R<sub>3sub>=2Ω、R<sub>4sub>=4Ω、R<sub>5sub>=5Ω,试求等效电阻R<sub>absub>。r /> rc="https://img.ppkao.com/2018-05/tangxueping/2018051015543465216.jpg" />
A、已知电路如图所示,其中E<sub>1sub>=15V,E<sub>2sub>=65V,R<sub>1sub>=5Ω,R<sub>2sub>=R<sub>3sub>=10Ω。试用支路电流法求R<sub>1sub>、R<sub>2sub>和R<sub>3sub>三个电阻上的电压。r /> rc="https://img.ppkao.com/2018-09/tangxueping/2018092817031193342.jpg" />
A、r<sub>1sub>=r<sub>2sub>=0,L<sub>1sub>=L<sub>2sub>=M=0 B、r<sub>1sub>=r<sub>2sub>=0,L<sub>1sub>=L<sub>2sub>=M=∞ C、r<sub>1sub>=r<sub>2sub>=∞,L<sub>1sub>=L<sub>2sub>=M=0 D、r<sub>1sub>=r<sub>2sub>=∞,L<sub>1sub>=L<sub>2sub>=M=∞
A、(R<sub>1sub>+R<sub>2sub>)/R<sub>1sub>R<sub>2sub> B、R<sub>1sub>R<sub>2sub>/(R<sub>1sub>+R<sub>2sub>) C、R<sub>1sub>+R<sub>2sub> D、R<sub>1sub>R<sub>2sub>