The c ircuit is shown in the figure, when the load RL gets maximum power, RL=________Ω. Choose A,B,C or D. We can use Thevenin theorem to make this cuirt a simple loop circuit consisted of an open circuit voltage Uoc , the equivalent resistor Roc and the load resistor RL, when RL=Roc, we can get the maximum power. Pmax= Uoc.^2/(4*Roc)