5. The crocodile clips will be attached securely.
6. I will repeat the experiment to ensure accurate results are obtained.
7. Keep the value of voltage at a constant level throughout the experiment.
Variables.
Dependent Variable - The value of resistance of the resistance wire.
Independent Variable - The length of the resistance wire.
Control Variable - The positioning of the amp and volt metre, the current flowing through the circuit.
Preliminary work.
From conducting preliminary work, I have been able to determine the appropriate lengths to use for the resistance wires. I have concluded that the lengths should range from 20mm to 200mm, and to increase every 20mm. I have also worked out how to set up the appropriate equipment in the appropriate order, as shown in the diagram below.
Hypothesis.
From my current knowledge an research of resistance, I am able to say that as theoretically, the value of resistance will increase with the increase in length of the resistance wire. Resistance wires are made of atoms molecules, it is these atoms and molecules which cause the resistance of the atoms and molecules that come in their way to pass through the circuit. The number of atoms and molecules that are in the resistance wire increase in proportion with the length of the resistance wire.It therefore seems reasonable to predict that the value of resistance will increase in proportion to the increase of the length of the wire.
Diagram.
This is an example of what our results table with look like:.
Length P.D Current Resistance R.
(mm) (volts) (amps) R = V/I (ohms).
Investigation Procedure.
The procedure for the experiment is as follows;.
1. Set up the experiment appropriately as shown in the diagram (when attaching the crocodile clips to the resistance wire, remember that the length of the wire starts at the tip of each crocodile clip).
2. Attach the crocodile clips to the resistance wire at the appropriate place, so that the wire is 20mm long.
