11 November Part 2 of Internal Resistance (AKA "the mystery of the lost volts")

These videos are from Steve4physics (not me) and give a really good, detailed explanation of internal resistance.

Part 1: Introduction - the basics



Part 2: Calculations - the basics



Part 3: Calculations - more complex



Part 4: Calculations - how to measure internal resistance N.B. the graphical method here plots Current on the y axis against terminal potential difference on the x axis.  Our exam board normally show the graphs the other way round, so the section after 5 minutes 19 seconds is less useful and might be confusing unless you are a very confident mathematician.