All Flashcards
How do dielectrics work to increase capacitance?
- Polarization: Molecules align with the electric field, creating an opposing field. 2. Reduced Electric Field: Net electric field is reduced. 3. Increased Capacitance: More charge can be stored at the same voltage.
Describe the process of charging a capacitor in an RC circuit.
Current flows into the capacitor, voltage across it increases over time, and the current decreases exponentially as the capacitor charges.
Describe the process of discharging a capacitor in an RC circuit.
Current flows out of the capacitor, voltage across it decreases over time, and the current decreases exponentially as the capacitor discharges.
What are the key differences between capacitors in series and parallel?
Series: 1/C_total = 1/C_1 + 1/C_2 + ... , Charge is the same, Voltage adds. | Parallel: C_total = C_1 + C_2 + ... , Voltage is the same, Charge adds.
Compare and contrast the behavior of a capacitor at t=0 and at steady state in a DC circuit.
At t=0: Capacitor acts like a short circuit, allowing maximum current flow. | At steady state: Capacitor acts like an open circuit, blocking current flow.
Compare charging and discharging in an RC circuit regarding current and voltage.
Charging: Current decreases exponentially, Voltage increases exponentially. | Discharging: Current decreases exponentially, Voltage decreases exponentially.
What is the definition of a capacitor?
A device that stores electrical charge and energy in an electric field.
Define capacitance (C).
The ability of a capacitor to store charge; measured in Farads (F), where 1 F = 1 C/V.
What are dielectrics?
Insulating materials placed between capacitor plates to increase capacitance.
What is the dielectric constant (κ)?
A value that quantifies how much a material increases capacitance when used as a dielectric.
What is an RC circuit?
A circuit consisting of a resistor and a capacitor connected in series, used for timing and filtering applications.
Define permittivity of free space (ε₀).
A physical constant that describes the ability of a vacuum to permit electric fields; approximately 8.85 x 10⁻¹² F/m.