Freiz Lessons on Potential Difference in Parallel Circuits

Objectives

• Describe how potential difference changes in parallel circuits.
• Calculate potential difference in parallel circuits.

Key Concepts

• Potential Difference (Voltage):

  • Indicates energy transfer in a circuit.
  • 1 Volt = 1 Joule of energy transferred per Coulomb of charge.

• Series Circuits:

  • Potential difference is split between components.

• Parallel Circuits:

  • Have branches through which current passes.
  • Potential difference across each component in parallel is the same.

Measuring Potential Difference

• Use a voltmeter to measure potential difference across components.
• In the example parallel circuit provided:
  • Potential difference across the cell = 6 Volts.
  • Potential difference across each branch (top and bottom lamp) = 6 Volts.

Key Fact

• For components in parallel, the potential difference across each component is identical.

Example Problems

• Problem 1:

  • Given: Potential difference across the bottom lamp = 12 Volts.
  • Find: Potential difference across the top lamp and the cell.
  • Solution:
    • Potential difference across the top lamp = 12 Volts.
    • Potential difference across the cell = 12 Volts.

• Problem 2:

  • Given: Two lamps in series within a parallel circuit.
  • Right hand lamp potential difference = 7 Volts.
  • Find: Potential difference across the bottom lamp.
  • Solution:
    • Left hand lamp potential difference = 2 Volts.
    • Total potential difference across bottom lamps = 9 Volts, same as the branch above and the cell.

Additional Resources

• More questions on potential difference in parallel circuits are available in the vision workbook.
• Access the workbook by clicking the provided link in the lesson.

Conclusion

• Now able to describe and calculate potential difference in parallel circuits.