A student investigates the resistances of different wires. Plan an experiment to investigate the resistances of wires made from different metals. Resistance is calculated using the equation R = The following apparatus is available: ammeter voltmeter power supply metre rule a selection of wires made from different metals, You can also use other apparatus and materials that are usually available in a school laboratory. In your plan, you should: write a list of suitable metals for the wires you will investigate draw a diagram of a suitable electrical circuit using standard electrical symbols explain briefly how to carry out the investigation state the key variables to keep constant