How do I calculate the Power lost by internal resistance? Please help.
My email: samuelfrancis16mes@gmail.com
Hi Samuel,
Good question.
We will represent the internal resistance as if it were a resistor. Normally you would be given, or be able to calculate two or more quantities relating to this ‘resistor’:

the current through this resistor

the voltage drop across this resistor

the resistance of this resistor
Given two of those, you should be able to use P=IV, P=I^2R, or P=V^2/R to calculate the power of the resistor.
There are a couple of alternative ways you could work it out, but I think the above would be a more likely approach for a L3 Physics paper.
If you’d like to post the question, and any relevant values, I’ll post a solution.