Current Electricity Concepts and Laws

Jul 24, 2024

Current Electricity Lecture Notes

Introduction

  • Detailed study of current electricity.
  • Try to understand definitely and make notes carefully.

Meaning of Current

  • Current means the flow of charge.
  • Current forms in any conductor.
  • Measurement of current (I) is done in coulombs.

Types of Current

  1. Transient Current

    • Flows for a very short time.
  2. Steady Current

    • Flows continuously.

Relation between Current and Resistance

  • The relation between resistance and current can be understood through Ohm's law.
  • Ohm's Law:
    • V = I × R
    • where
      • V = Voltage
      • I = Current
      • R = Resistance

Kirchhoff's Laws

  1. Junction Rule

    • The incoming and outgoing current at a junction must be equal.
    • [ I_{in} = I_{out} ]
  2. Voltage Rule

    • The total voltage in a closed loop is zero.
    • [ ext{Total Voltage} = 0 ]

Definition of Watt and Power

  • Power is measured in watts.
  • Power = Voltage × Current = [ P = V × I ]

Electrical Energy

  • Usage of energy is in percentage.
  • Energy = Power × Time
  • Types of energy of storage battery.

Heating Effect of Current

  • Heat is produced when current passes through a resistance.
  • [ H = I^2 × R × t ]

Wheatstone Bridge

  • An arrangement of four resistances, where one resistance is unknown.
  • When there is no current at the junction, it is balanced.

Conduction (Practices)

  • Practices can be understood by sign convention at junction and potential.

Conclusion

  • It is important to consolidate and understand the principles and practical knowledge of current electricity.
  • Prepare well to answer questions regarding this.

Important to Remember:

  • Sign and style of resistance: Increasing resistance decreases current.
  • Conservation of Charge: Always remember that the current entering a junction is equal to the current leaving.
  • Use Kirchhoff's both laws effectively.

Next Class:

  • Deep study of current electricity.

Attention for Participants:

  • All students must strictly follow the study guidelines.
  • Continuous practice and preparation of questions.

!!! Congratulations, keep up the work !!!