A student is investigating how the resistance of a wire depends on its cross-sectional area. The student aims to plot a graph of resistance RRR against the reciprocal of the cross-sectional area 1/A1/A1/A.
The following apparatus is available to the student:
- ammeter
- voltmeter
- power supply
- variable resistor (rheostat)
- switch
- connecting leads
- micrometer screw gauge
- five resistance wires of different diameters, all made of the same material
- metre rule
Plan an experiment to investigate how the resistance of a wire depends on its cross-sectional area.
You should:
- describe a circuit diagram you would use to determine the resistance of each wire (stating how components are connected)
- explain briefly how you would carry out the investigation, including how you would determine the cross-sectional area of each wire
- suggest five suitable diameters of wire
- state the key variables that you would control
- draw a table, or tables, with column headings to show how you would display your readings. (You are not required to enter any readings in the table.)