The venomous Red-Bellied Black Snake grows to lengths of up to two metres long, and has striking colouration. With stunning red edges to its belly scales and a shiny black back, this snake surely ranks amongst Australia's most stunning venomous snakes.
For other uses, see EMF (disambiguation). Electromotive force, also called emf (denoted E {\displaystyle {\mathcal {E}}} and measured in volts), is the voltage developed by any source of electrical energy such as a battery or dynamo. It is generally defined as the electrical potential for a source in a circuit.
What are the emf and internal resistance of the battery in the figure below? I have the answers, that emf is 9V and internal resistance is 0.5 ohms, however I'm having problems getting there. So then the internal resistance and that new Req are in series, so Req = r + 10/3 ohms. Now, I come to my problem.