# Resistance in a Wire Coursework

1540 Words7 Pages
Resistance in a Wire Coursework In this investigation we are trying to look for resistance in a piece of wire, and how the length of a wire can increase or decrease the resistance. The things that affect the resistance in a wire are: • the length of the wire • a certain amount of wire • cross sectional area of the wire (thickness) • temperature • material What things can affect the resistance in a wire? The temperature can affect the resistance in a wire, because the more thermal energy a component has the more the atoms within it will vibrate and get in the path of the “free” electrons, so the higher the temperature, more resistance is being produced. Material can affect the resistance due to the number of “free”…show more content…
• The thickness of the wire decreases. • Once you have figured out the thickness of the wire (length x width), you will be able to calculate the ohms law. Prediction My prediction for this experiment is, once the length of the wire increases, so will the resistance. What my results show me My results show me that once the readings on the ammeter and the voltage increase, so will the resistance, because of this we decided to increase the length of wire used by 10cm each time a reading was recorded. Method 1. Set up the series circuit. 2. Connect the crocodile clip to 30cm along the wire. 3. Switch on the power supply. 4. Record readings from the ammeter and voltmeter. 5. Switch off the power supply. 6. Repeat the stages of 2-6 three times at length 30cm intervals up to 1 metre. What I did and why I kept my experiment a fair test in the following ways: I did not change any parts of the circuit (wires, ammeter, voltmeter or battery pack) in between the measurements – this would have prevented small discrepancies between circuit components from affecting the results. When taking the measurements from the voltmeter and ammeter, I waited for the reading to settle completely. If it didn’t settle, then I would have made an estimate of the middle value being shown. Waiting for the reading to settle prevented accidentally taking a reading while the value is fluctuating randomly when the power is first turned