I understand how to find Thevenin equivalents when the are independent sources in the circuit, but once dependent ones are introduced, I get a little nervous.
Here's what I did:
I found the open circuit voltage which is equivalent to voltage Vb relative to ground by doing the node voltage method. I found Vb = 10V.
Then I considered the circuit in the short circuit condition in which an addition connection from node B to ground is made. In this condition, I found the short circuit current to be 4mA.
Thus, the Thevenin equivalent resistor is given by 10V/4mA = 2.5 kOhms. Therefore, the Thevenin equivalent circuit is a 10V voltage source connected to a 2.5 kOhm resistor.
How can I check to see if my answer is correct though?