Two metallic wires P and Q of equal length are supplied to you. You are asked to compare their resistances using the laboratory apparatus normally available for the verification of Ohm’s law.
(i) With the help of a neat, labelled circuit diagram, describe how you would arrange the apparatus to measure the resistance of each wire one after the other using the same battery and ammeter–voltmeter combination.
(ii) List two precautions you would observe to obtain reliable readings.
(iii) The following readings were obtained for each wire when the potential difference across them was maintained at 3.0V.
For wire P: current 0.50A
For wire Q: current 0.80A
Calculate the resistance of each wire.
(iv) Which wire is likely to have the larger diameter? Give a brief reason based on your calculations.