A $12\,\text{V}$ battery is connected in series with an ammeter, a $2\,\Omega$ fixed resistor and a $0\! -\! 10\,\Omega$ variable resistor. High-resistance voltmeters $P$ and $Q$ are placed across the variable resistor and the fixed resistor respectively, as shown. The resistance of the variable resistor is altered from its maximum value to zero. Which graph shows how the voltmeter readings vary with current?
Physics 9702 · AS & A Level · Potential difference and power