All Flashcards
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 effect of increasing the area of the plates on a parallel plate capacitor?
Increases the capacitance (C = ε₀A/d).
What is the effect of increasing the distance between the plates of a parallel plate capacitor?
Decreases the capacitance (C = ε₀A/d).
What happens when a dielectric is inserted between the plates of a capacitor?
The capacitance increases (C = κ(ε₀A/d)).
What happens to a capacitor in a DC circuit at steady state?
It acts as an open circuit, blocking current flow.
What happens to the energy stored in a capacitor if the voltage across it is doubled?
The energy stored quadruples (U = 1/2 CV²).
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.