LESSON-1-Capacitors-and-Electric-Circuit

General Concepts

• Electricity Basics

  • Study of electric currents and circuits.

Capacitor

• Definition

  • A capacitor is a passive device that stores electrical charge when connected to a voltage source.

Capacitor Structure

• Basic Form

  • Comprises two or more parallel conductive plates separated by an insulating layer called the dielectric.

Capacitance

• Definition

  • Capacitance measures a capacitor's ability to store charge, measured in Farads (F), named after Michael Faraday.

• Units of Capacitance

  • Millifarad (mF): 1 mF = 0.001 F

  • Microfarad (μF): 1 μF = 0.000001 F

  • Nanofarad (nF): 1 nF = 0.000000001 F

  • Picofarad (pF): 1 pF = 0.000000000001 F

    Capacitance Value - the amount of electric charge that can be store on its plates

Factors Affecting Capacitance

• Surface Area (A)

  • Larger plates = greater capacitance.

• Distance (d)

  • Shorter distance = greater capacitance.

• Dielectric Material

  • Material used affects capacitance; higher permittivity = greater capacitance.

Key Formulas

• Capacitance Formula

  • C = ε0 * (A/d)

  • ε0 = permittivity of free space (8.85 x 10^-12 C²/N·m²)

  • A = plate area (m²), d = distance between plates (m).

• Charge Stored

  • Q = C * ∆V

  • Q = charge in Coulombs (C), C = capacitance in Farads (F), ∆V = voltage in Volts (V).

Electric Circuits

• Definition

  • A circuit is a path for electric current, comprising a power source, conductors, load, and switches.

Types of Circuits

• Series Circuit

  • Components connected in a single path with no branches.

• Parallel Circuit

  • Components connected with multiple paths for electricity flow.

• Open Circuit

  • Breaks current flow.

• Closed Circuit

  • Complete path for current flow.

• Short Circuit

  • Low-resistance path causing excessive current flow.

Capacitors in Arrangements

• In Series

  • Identical charge across capacitors.

  • Use formula:

    • 1/C_total = 1/C1 + 1/C2 + 1/C3

• In Parallel

  • All positive and negative plates connected together.

  • Use formula:

    • C_total = C1 + C2 + C3

Example Calculations

• Capacitance Example

  • Find total capacitance in series and parallel arrangements based on sample values.