resistance

• step 1

  attach a crocodile clip to the wire level with 0cm on the ruler
• step 2

  attach second crocodile clip to the wire, write down the length of wire between the clips
• step 3

  close the switch and record the current through the wire and the pd across it
• step 4

  open the switch and move the second crocodile clip

  close the switch and record the new length, current and pd
• step 5

  repeat this for different lengths of wire
• step 6

  use the pd and current measurements to calculate resistance

  V=I x R