Resistance Of Wire Required Practical

Question 1

What is the method for a resistance of wire required practical

Answer 1

• Attach a crocodile clip to the wire level with 0cm on the ruler
• Attatch a second crocodile clip 10 cm away from the first crocodile clip. Record the distance between the crocodile clips
• Close the switch and record the current through the wire and the potential difference across it
• Open the switch and move the second crocodile clip another 10cm along the wire . Record the new length , pd and current
• Repeat this for a number of different lengths of wire
• Use the measurements of current and potential difference to calculate the resistance of different lengths of wire

Question 2

What are some things you must do for this required practical

Answer 2

• Make sure the crocodile clip is exactly at zero . If it is not it could cause all of the results to be slightly off
• Use a low potential difference to keep current low . This reduces any heating in the wire which could increase resistance
• Only turn the current on when taking readings , turn it off between readings