11.5 Capacitors and Capacitance

• A capacitor stores electrical charge and energy in an electrical field
• The formula for capacitance is $C =$$\frac{Q}{V}$, where C is capacitance, Q is charge, and V is voltage
• Order the relationships between capacitance and its factors:

  1️⃣ Area of plates (A) - Directly proportional

  2️⃣ Distance between plates (d) - Inversely proportional

  3️⃣ Type of insulator (ε) - Directly proportional
• Capacitors store electrical charge by accumulating it on their plates
• What is the relationship between capacitance and the area of the plates?

  Directly proportional
• How does the distance between the plates affect capacitance?

  Inversely proportional
• The formula for capacitance is $C =$$\frac{Q}{V}$.


  True
• A capacitor stores energy in the form of an electric field.
• What is the unit of capacitance?

  Farad
• What is the formula for capacitance?

  $C =$$\frac{Q}{V}$
• What unit is used to measure charge?

  Coulomb
• What is the formula for total capacitance in a series combination?

  C_{eq} = \frac{1}{\frac{1}{C_{1}} + \frac{1}{C_{2}} + \ldots + \frac{1}{C_{n}}}</latex>
• In a series combination, the charge is the same across each capacitor
• The energy stored in a capacitor is measured in Joules
• What is the formula for the time constant in an RC circuit?

  $\tau =$$RC$
• What is the time constant of an RC circuit with R = 1000 Ω and C = 10 μF?

  $0.01 \text{ s}$
• What is capacitance a measure of?

  Ability to store charge
• The capacitance of a capacitor depends on the area of the plates, the distance between them, and the type of insulator
• A capacitor with larger plates has a lower capacitance than one with smaller plates.

  False
• The closer the plates of a capacitor, the greater the capacitance.


  True
• The capacitance of a capacitor increases with the area of its plates.


  True
• What type of capacitor has the highest capacitance?

  Large plates, close together
• What is a capacitor primarily used for?

  Storing electrical charge
• A capacitor with a high dielectric material has a lower capacitance.

  False
• The formula $C =$$\frac{Q}{V}$ defines the relationship between capacitance, charge, and voltage.
• Capacitance is measured in Farads.

  True
• A higher capacitance allows more charge to be stored at a given voltage.


  True
• The voltage is the same across each capacitor in a parallel combination.


  True
• What is the formula for the energy stored in a capacitor?

  U = \frac{1}{2}CV^{2}</latex>
• How much energy is stored in a 10 μF capacitor charged to 100 V?

  $0.05 \text{ J}$
• During charging, the current in an RC circuit decreases exponentially towards zero.


  True
• Capacitors store energy in the form of an electric field between conductors.

  True
• Match the variable with its unit and explanation:

  Charge (Q) ↔️ Coulomb (C) - The amount of electrical charge stored on the capacitor's plates.

  Voltage (V) ↔️ Volt (V) - The potential difference across the capacitor's plates.

  Capacitance (C) ↔️ Farad (F) - A measure of the capacitor's ability to store charge.
• What type of insulator will increase the capacitance of a capacitor?

  High dielectric material
• Match the variable with its unit and explanation:

  Charge (Q) ↔️ Coulomb (C) - The amount of electrical charge stored on the capacitor's plates.

  Voltage (V) ↔️ Volt (V) - The potential difference across the capacitor's plates.

  Capacitance (C) ↔️ Farad (F) - A measure of the capacitor's ability to store charge.
• What is capacitance a measure of?

  Ability to store charge
• The type of insulator material between the plates affects the capacitance.
• Match the variable with its unit and description:

  Capacitance ↔️ Farad (F) ||| Charge stored per volt

  Charge ↔️ Coulomb (C) ||| Electrical charge stored

  Voltage ↔️ Volt (V) ||| Potential difference
• What is the formula for charge stored in a capacitor?

  $Q =$$CV$
• What is the unit of charge?

  Coulomb