A student designs an experiment to investigate how the resistivity of a metal wire varies with temperature by heating a coil of the wire in a water bath and measuring its resistance.
Which of the following experimental actions is performed specifically to ensure the validity of the investigation?
Repeating the resistance measurements at each temperature and calculating a mean
Measuring the wire's diameter with a micrometer at several different positions and orientations
Keeping the current in the coil extremely low to prevent self-heating of the wire
Calibrating the digital temperature sensor using an ice-point bath before starting
Practise AQA A Level Psychology Scientific processes with exam-style questions for A Level Psychology. 689 questions, matched to the AQA A Level Psychology (7182) specification and written in Paper 1, Paper 2 and Paper 3 style. Every question includes a full worked solution and mark scheme, so you can see where marks are awarded rather than just whether you got the answer right.
