Capacitive Circuits - Alternating Currents

1. Capacitance and Capacitors

• Capacitance: NCERT Physics Part 2, Chapter 2: Electrostatic Potential and Capacitance (Class 12).
  • Definition of capacitance and its unit (farad).
  • Factors affecting capacitance:
    • Plate area.
    • Distance between plates.
    • Dielectric material.
• Types of Capacitors:
  • Polar and non-polar capacitors.
  • Electrolytic capacitors.
  • Ceramic capacitors.
• Capacitor Charging and Discharging Process:
  • Explain the process of charging and discharging a capacitor with relevant equations.

2. AC Circuits:

• Alternating Current (AC): NCERT Physics Part 2, Chapter 7: Alternating Current (Class 12).
  • Introduction to AC and its characteristics.
  • Generation of AC voltage using an alternator.
  • Representation of AC waveforms (sinusoidal curves).
• Key AC Concepts:
  • Frequency
  • Period
  • Amplitude
  • Phase angle

3. Capacitors in AC Circuits:

• Capacitive Reactance:
  • Definition and formula of capacitive reactance.
  • Dependence of capacitive reactance on frequency.
• Phase Difference:
  • Explain the phase difference between voltage and current in a capacitive circuit.
• Capacitive Impedance:
  • Define capacitive impedance and its calculation.

4. Capacitors in Series and Parallel:

• Capacitors in Series:
  • Equivalent capacitance formula for capacitors in series.
  • Voltage and current distribution in series capacitor circuits.
• Capacitors in Parallel:
  • Equivalent capacitance formula for capacitors in parallel.
  • Voltage and current distribution in parallel capacitor circuits.

5. RC Circuits

• RC Circuit Analysis:
  • Charging and discharging of RC circuits.
  • Time constant of RC circuits and its significance.
  • Applications of RC circuits (timing circuits, filters, etc.).

6. Resonance in Capacitive Circuits

• Resonance:
  • Explain resonance and its significance in AC circuits.
• Series and Parallel Resonance:
  • Conditions for series and parallel resonance.
• Quality Factor (Q-Factor):
  • Define Q-factor and its impact on resonance.

7. Power Factor and Power in Capacitive Circuits:

• Power Factor:
  • Definition of power factor and its importance.
• Power Factor Improvement:
  • Explain how capacitors can improve power factor.
• Power Calculations:
  • Calculation of average power and reactive power in capacitive circuits.

8. Applications of Capacitors in AC Circuits:

• Energy Storage Devices:
  • Capacitors as energy storage devices in AC circuits.
• Smoothing Filters:
  • Capacitors in smoothing filters of power supplies.
• Coupling and Decoupling Capacitors:
  • Explain the use of capacitors for coupling and decoupling in circuits.
• AC Motor Starting:
  • Capacitors in AC motor starting circuits.