A、P=Uup>2up>/R B、P=U/I C、P=U/R D、以上都正确
A、R=0.012526P/H B、R=0.006263P/H C、R=0.004178P/H D、R=0.00051P
A、R=0.012526P/H B、R=0.006263P/H C、R=0.004178P/H D、R=0.00051P
A、U=Uub>Rub>+Uub>Lub> B、u=uub>Rub>+uub>Lub> C、Cosφ=P/S D、Cosφ=R/L