Course Content
S-1 General Safety Rules S-2 Effects of Electric Current S-3 On The Job S-4 Protective Clothing S-5 Ladders & Scaffolds S-6 Fires S-7 Ground Fault Circuit Interrupters S-8 Grounding
Unit 1 – Atomic Structure
Objectives After studying this unit, you should be able to: List the principal parts of an atom State the law of charges Discuss the centripetal force  Discuses the differences between conductors & insulators Preview Electricity is the driving force that provides most of the power for the industrialized world. It is used to light houses, cook meals, heat and cool building, run electric motors, & supplies ignition for most automobiles in the world, 
Electrical Theory Fundamentals
About Lesson

Parallel circuits are an essential concept in electrical engineering and are commonly found in various electrical systems. Understanding how parallel circuits work is crucial for designing and analyzing complex electrical networks. In this lesson, we will explore the characteristics, calculations, and behavior of parallel circuits. Let’s get started!

  1. Definition and Characteristics: A. Definition:

    • Define a parallel circuit as a circuit configuration where components are connected across the same voltage source, forming multiple paths for current flow.
    • Emphasize that the voltage across each component in a parallel circuit is the same.

    B. Characteristics:

    • Discuss the key characteristics of parallel circuits, such as:
      • Components share the same voltage.
      • The total current is divided among the components.
      • Adding or removing components does not affect the others.
  2. Calculating Total Resistance: A. Resistors in Parallel:

    • Explain how to calculate the total resistance when resistors are connected in parallel.
    • Discuss the formula: 1 / Total Resistance = 1 / R1 + 1 / R2 + 1 / R3 + … + 1 / Rn.

    B. Example Calculation:

    • Provide an example parallel circuit with multiple resistors and guide students through the calculation of total resistance.
    • Include practice exercises for students to reinforce the concept.
  3. Calculating Total Current: A. Current Division Rule:

    • Explain the current division rule in parallel circuits.
    • Discuss how the total current entering the circuit is divided among the parallel branches based on their individual resistances.

    B. Example Calculation:

    • Provide an example parallel circuit with multiple resistors and guide students through the calculation of current flowing through each branch.
    • Emphasize that the sum of individual currents should equal the total current entering the circuit.
  4. Calculating Total Resistance with Identical Resistors: A. Simplified Formula:

    • Explain that if all resistors in a parallel circuit are identical, a simplified formula can be used.
    • Discuss the formula: Total Resistance = (Resistance of One Resistor) / (Number of Identical Resistors).

    B. Example Calculation:

    • Provide an example parallel circuit with identical resistors and guide students through the calculation of total resistance using the simplified formula.
    • Reinforce the concept with practice exercises.
  5. Practical Applications and Considerations: A. Household Electrical Wiring:

    • Discuss how parallel circuits are used in household electrical wiring.
    • Explain that multiple electrical outlets in a room are connected in parallel, allowing independent operation without affecting others.

    B. Christmas Tree Lights:

    • Discuss how parallel circuits are utilized in Christmas tree lights.
    • Explain that if one bulb burns out, the others remain lit due to the parallel connection.
  6. Advantages and Disadvantages of Parallel Circuits: A. Advantages:

    • Discuss the advantages of parallel circuits, such as independent operation of components, reliability, and easy troubleshooting.

    B. Disadvantages:

    • Highlight the disadvantages of parallel circuits, such as higher complexity, increased wiring, and higher cost compared to series circuits.

Conclusion: Congratulations! You have learned the fundamentals of parallel circuits. You now understand their characteristics, how to calculate total resistance and current, and the behavior of voltage in parallel circuits. Remember that parallel circuits are widely used in electrical systems, offering independent operation and increased reliability. Continue practicing and applying these concepts to further your understanding of electrical circuits and network analysis.

Join the conversation