Announcements

• Lab Announcements

  • Lab starts this week, specifically on Tuesday.
  • Students are advised to check for announcements regarding Lab One via Canvas from their TAs.
  • Lab safety procedures were covered via Zoom.

• Lab One Content

  • Theoretical concepts of series and parallel resistors are to be covered in a later class.
  • Practical component will include usage of a multimeter.
  • Videos on how to use a digital multimeter and breadboard are available.
  • Resistance values like 10 kΩ or 1 kΩ will typically be provided, but the process to measure resistance will also be shared.

• Homework Assignments

  • No homework for the first week as no material has been covered yet.
  • Homework One will be based on material covered today, to be posted on Canvas.
  • Problem-solving sessions scheduled for Wednesday and Friday to assist with Homework One, which is due the following Monday.

Course Content Overview

• Chapters Covered

  • Chapter One and Two from the textbook have been initiated.
  • Topics covered span from sections 1.0 to 2.0.
  • Homework and problems should be consulted in these chapters.

• Passive Sign Convention

  • Used for determining the sign of voltage and current in circuit analysis.
  • Voltage and current direction determines whether a plus or minus sign is assigned.
    • If current flows in the same direction as voltage drop, assign a positive sign to V or P.
    • If current flows in the opposite direction, assign a negative sign.

• Power Calculation

  • Power can be expressed as:
    • $P = VI$
    • If current and voltage are in opposite directions: $P = -VI$.
  • Alternative forms: $P = I^2 R$ or $P = \frac{V^2}{R}$.

Electrical Circuit Components

• Voltage Drop Analysis

  • Introduced the relationship between voltage drop and current in the context of circuit elements.
  • Explained concept of resistive elements:
    • Common materials like copper and aluminum do not behave as resistors as they are good conductors.
    • Resistance is defined as impeding the flow of electrical current.

• Independent vs Dependent Sources

  • Independent Voltage Source: Provides constant voltage across terminals regardless of current flow.
  • Dependent Voltage Source: Voltage value depends on another variable current in the circuit.
    • Example shown in diagrams to highlight independence.

Kirchhoff's Laws

• Introduction to Kirchhoff's Laws
  • To analyze circuits when only using Ohm's Law is insufficient.
  • Includes two main laws: Kirchhoff's Current Law (KCL) and Kirchhoff's Voltage Law (KVL).

Definitions

Kirchhoff's Current Law (KCL)

• States that the algebraic sum of currents entering a node is zero.
  • Currents entering = Currents leaving at any circuit node.

Kirchhoff's Voltage Law (KVL)

• States that the algebraic sum of all voltages in any closed loop would equal zero.

  • Loop direction (clockwise or counterclockwise) can affect positive or negative sign assignments.

• Node and Loop Definitions

  • Node: A point where two or more circuit components meet.
  • Loop: A closed path through the circuit components.

Example Applications of KVL and KCL

• KVL Example

  • Voltage drops were defined in respect to chosen loop direction.
    • Example circuit discussed with voltage assignments across components:
      • The sum of voltage rises and drops equates to zero.

• KCL Example

  • Analysis of currents entering and leaving the node.
    • Statement: $I<em>{in} = I</em>{out}$ simplified to $I<em>1 - I</em>2 - I_3 = 0$

• Power and Energy Calculations

  • Practical advice on measuring using a multimeter to assist with problem-solving.
  • Importance of correct polarity and direction emphasized for precision in electrical measurements.