An ideal voltmeter connected across a certain fresh 9V battery reads 9.30 V and an ideal ammeter briefly connected across the same battery reads 3.70 A. We say the battery has an open-circuit voltage of 9.30 volt and a short-circuit current of 3.70 A. Model the battery as a source of emf In series with an internal resistance r as shown in the figure. Determine the emf
