BIOLOGY

PHOTOSYNTHESIS
Investigation - Resistance of a Wire

Aim: The resistance of a wire depends on certain factors. Investigate the effect of two of these factors –

Planning

Some variables that will be relevant to this investigation are:

Length
Thickness
Temperature
Voltage
Resistance
Material
Of these the variables will be input and output voltages in experiment one, and length and resistance in experiment two. The other variables (temperature, material and voltage) will have to be kept constant in both experiments to make sure that only length, thickness and resistance are investigated. In experiment 1 the same bit of wire and the same thickness need to be kept constant. In experiment 2, the length will need to be kept constant to make sure only the variables indicated are investigated to ensure a fair test.

Metals conduct electricity because the atoms in them do not hold on to their electrons very well, and so creating free electrons, carrying a negati...