Find resistance R so that maximum power is transferred to this resistor.
Rth = Voc/Isc
The Attempt at a Solution
I tried to find the Thevenin equivalent circuit across the resistor R because the Thevenin resistance must be equal to the load resistor in order for maximum power to be transferred.
I replaced R with an open circuit to find the open circuit voltage.
Using Nodal Analysis, I obtained the equation: (V1 - 4V)/5 + V1/15 = 0
So, V1 = 3 = Voc.
Then I redrew the circuit and replaced R with a short circuit and solved for two voltages at the nodes.
I used Nodal Analysis and obtained two equations.
[3Vx = V2/6]
(V1-4V)/5 + V1/15 + V2/2 + (V1-V2)/5 = 0
V2/6 + (V2-V1)/5 = 3V2/6
I got V1 = 48V, V2 = -72V and Isc = V2/6 = -12A
so I got Rth = 3/-12 = -0.25 ohms.
This isn't right, but I"m not sure what I did wrong.