AP Physics 2: Algebra-Based Flashcards: Resistor-Capacitor (RC) Circuits
Written by AP Content Team, Verified for 2026 AP Exams, Last updated: May 2026
Review key ideas with interactive flashcards. This set includes 11 cards to help you master important concepts.
What physical quantities determine the time constant of an RC circuit?
The time constant is determined by the product of the circuit's equivalent resistance (R_eq) and equivalent capacitance (C_eq).
Card 1 of 11
All Flashcards (11)
What physical quantities determine the time constant of an RC circuit?
The time constant is determined by the product of the circuit's equivalent resistance (R_eq) and equivalent capacitance (C_eq).
Does connecting capacitors in parallel increase or decrease the total equivalent capacitance?
Connecting capacitors in parallel always increases the total equivalent capacitance of the combination.
What does a larger time constant (τ) imply about the charging process of a capacitor?
A larger time constant implies that the capacitor will take a longer amount of time to charge or discharge.
In a DC circuit, how does a fully charged capacitor behave with respect to current flow?
A fully charged capacitor effectively acts as an open switch or a break in its circuit branch, allowing zero current to flow through it.
Does connecting capacitors in series increase or decrease the total equivalent capacitance?
Connecting capacitors in series always decreases the total equivalent capacitance of the combination.
How do you calculate the equivalent capacitance for multiple capacitors connected in parallel?
The equivalent capacitance of capacitors in parallel is the direct sum of the individual capacitances (C_eq,p = Σ C_i).
How do you calculate the equivalent capacitance for multiple capacitors connected in series?
The inverse of the equivalent capacitance of capacitors in series is the sum of the inverses of the individual capacitances (1/C_eq,s = Σ 1/C_i).
What is the state of a charging capacitor in a DC circuit after a very long time?
After a long time, the capacitor becomes fully charged, reaching its maximum potential difference, and the current in the branch containing the capacitor drops to zero.
What is the time constant (τ) of an RC circuit?
The time constant (τ) is a measure of how quickly a capacitor charges or discharges, defined by the equation τ = R_eq * C_eq.
To build an RC circuit with the fastest possible discharge time using a given resistor, how should you combine multiple capacitors?
To achieve the fastest discharge (smallest time constant), you must minimize the equivalent capacitance by connecting the capacitors in series.
If you replace a capacitor in a simple RC circuit with one that has a larger capacitance, what happens to the time constant?
Since the time constant is τ = RC, increasing the capacitance (C) while keeping the resistance (R) the same will increase the time constant.