How can I calculate the voltage on the load in this circuit?
As was suggested in your previous question, redrawing the circuit may help:


Thevenin Theorem to find the equivalent Thevenin Voltage (using the Voltage Divider Rule =&gt; E_Th = 6V) and also the Thevenin Resistance (we take R_s and R in parallel and the result is going to be 5k (Ohms)).

OK. So that would result in the following circuit:

From that, what is your reasoning regarding \$I_D\$?