Resistance of a Wire

• What does the resistance of a wire depend on?

  Length of the wire
• What is the purpose of investigating the length of a wire?

  To understand how it changes resistance
• What material might you have used in the experiment instead of wire?

  Carbon rod
• What are the steps to measure resistance in a wire?

  1. Set up the circuit as shown
  2. Start with a 5 cm length of wire
  3. Record the current and potential difference
  4. Repeat with longer lengths of wire
  5. Plot a graph of wire length vs resistance
• What should the results of the resistance experiment show?

  They should be directly proportional
• What happens if the wire is allowed to heat up during the experiment?

  A curve is produced instead of a straight line
• How can you avoid the wire heating up during the experiment?

  Disconnect the battery when not in use
• What should you do to ensure accurate results in the experiment?

  Connect the battery when needed only
• What common errors might occur in the resistance experiment?

  • Wire heating up causing inaccurate readings
  • Poor connections leading to resistance changes
  • Incorrect length measurements of the wire