A student is investigating how the resistance of a wire depends on its cross-sectional area. The student aims to plot a graph.
The following apparatus is available to the student:
- ammeter
- voltmeter
- power supply
- variable resistor
- switch
- connecting leads
- resistance wires of the same material and length, but with different diameters
- micrometer screw gauge
- metre rule
Plan an experiment to investigate how the resistance of a wire depends on its cross-sectional area.
You should:
- draw a diagram of the circuit you could use to determine the resistance of each wire
- explain briefly how you would carry out the investigation, including how the cross-sectional area is determined
- suggest a suitable range of wire diameters and the number of different wires to use
- state the key variables that you would control
- draw a table, or tables, with column headings to show how you would display your readings and calculated values. You are not required to enter any readings in the table.