Capacitance

• What are capacitors used for in electronic circuits?

  To store energy for backup
• What is the structure of a parallel plate capacitor?

  Two conductive metal plates connected to voltage
• What is the purpose of the dielectric in a capacitor?

  To prevent charge from flowing freely
• What is the circuit symbol for a capacitor?

  Two parallel lines

  
• How is capacitance defined?

  Charge stored per unit potential difference
• What happens to energy storage as capacitance increases?

  Energy stored increases with greater capacitance
• What is the formula for capacitance?

  C = Q / V

  
• What unit is capacitance measured in?

  Farad (F)
• Why is 1 Farad considered a large unit?

  Because practical capacitors are often smaller
• What are smaller units of capacitance often used?

  Microfarads, nanofarads, picofarads
• What does the charge Q represent in a capacitor?

  The charge stored on the plates

  
• What does the capacitance equation indicate?

  Capacitance is the ratio of charge to voltage

  
• If a capacitor has a capacitance of $1 \text{ nF}$ and a voltage of $0.3 \text{ kV}$, what is the charge on the plates?


  $300 \text{ nC}$
• What happens to polar molecules in a dielectric when an electric field is applied?

  • Molecules align with the electric field
  • Positive ends face negative plate
  • Negative ends face positive plate

  
• What does the term 'charge stored' refer to in a capacitor?

  The charge on each plate of the capacitor
• What is the significance of the letter 'C' in capacitance?

  It represents both capacitance and charge unit

  
• How do polar molecules behave when no charge is applied to the capacitor?

  They are aligned in random directions

  
• What occurs when a charge is applied to a parallel plate capacitor?

  An electric field is generated between the plates
• How does the alignment of polar molecules change when an electric field is present?

  They rotate and align parallel to the field