1. A battery with an internal resistance of 0.50 ohms has a current of 0.78A through it when it is connected in a circuit whose external resistance is 1.50 ohms. In this circuit, what is the potential difference between the terminals of the battery?
2. Power is being transmitted through normal transmission lines from a generator to a substation. If the input voltage is doubled and the current halved, how will the power input and the useful power output change?