Using the diode equation:

Just want to know whether I have the right idea: so to determine the reverse saturation current (Is), I just determine it for each value of Vd that was given? So finding Is for 0.6, 0.65, 0.7 etc?

The question seems to be divided into two parts, one that just asks for the reverse saturation current, and then to sketch a graph for points Vd=0.6, 0.65 etc. But it's not as if we're already given an initial Vd value to determine the reverse saturation current, so I'm guessing you just find it for the various values given?

Also, for plotting the load line part, I understand that I will be drawing my load line from 12V to an Id value. How do I determine this Id value? I'm guessing I need to find the line equation, but I'm not sure how to do that because of the diode. Do I just model the diode as a resistor in series with a voltage source? But then again, I haven't been given the Rd and Von value for this configuration..

Thanks.