1. The problem statement, all variables and given/known data The problem is actually longer, but I will make it shorter, just to ask my question. A flashlight battery has a voltmeter connected across its terminals. The voltmeter reads 1.50 V. (Assume the voltmeter is perfect, with an infinite resistance, drawing no current.) The voltmeter is removed and the battery is connected to a small light bulb. It turns out the potential drop across the bulb is only 1.42 V, because of the internal resistance of the battery. 2. Relevant equations 3. The attempt at a solution My question is why didn't the internal resistance of the battery record on the first reading of the voltage also? This isn't a question in the problem, I just don't understand why. There was a closed circuit in both cases. Any ideas greatly appreciated.