I was reading the post Which dissipates more power, a small or big resistor? and DanielSank's reply said
Now, any circuit you would reasonably call a "voltage source" must have a low internal resistance compared to typical load resistances. If it didn't then the voltage across the load would depend on the load resistance, which would mean your source isn't doing a good job of being a fixed voltage source.
If we're connecting a load to the battery, this would be in series.
Ri = 1 Ohms Fixed voltage source at 9V I = V/Ri = 9A
If we add R load in the mix, it is series so the current is the same in the circuit. How are we going to get the voltage to be fixed other than R load to be identical or similar values to Ri? Wouldn't the voltage drop between two resistance add up to the total voltage?