A 12V battery is connected in series with resistors of 4Ω and 6Ω. Points P, Q and R are located such that P is the positive terminal of the battery, Q is the junction between the two resistors and R is the negative terminal of the battery.
(a) Calculate the current flowing in the circuit.
(b) Determine the potential difference between points Q and R.
(c) The student wishes to measure only the potential difference across the 6Ω resistor. Identify the two points between which the voltmeter should be connected. Justify your answer.
(d) If the voltmeter is mistakenly connected between points P and Q, what numerical value will it show? Explain why this value differs from your answer in part (b).