Skip to main content

Learning Introductory Physics with Activities

Paul J. Emigh, Rebecka Tumblin, Kathryn Hadley, Danielle Skinner

Section 26.2 RC Charging Circuits

Subsubsection Activities

Activity 26.2.1. Derivative Warm-up.

What is the derivative of the function \(f(t) = Ae^{-\omega t}\) with respect to \(t\text{?}\)
🔗
🔗
The circuit below contains a battery, a resistor, a switch, and a capacitor. The capacitor is initially uncharged and the voltage of the battery is \(V\text{.}\)
🔗
A circuit diagram with a battery, open switch, light bulb, and capacitor.
Figure 26.2.1. A circuit diagram with both a light bulb and a capacitor.
🔗

Activity 26.2.2. Prediction 1.

Just after the switch is closed: what is the absolute value of the potential difference across the capacitor? Explain your reasoning.
🔗
🔗

Activity 26.2.3. Prediction 2.

A long time after the switch is closed: what is the absolute value of the potential difference across the capacitor? Explain your reasoning.
🔗
🔗

Subsubsection Key Ideas

🔗
When the capacitor is charging, the current through the resistor as a function of time is given by
\begin{equation*} I(t) = \frac{V_{bat}}{R}e^{-t/RC} \end{equation*}
🔗

Activity 26.2.4. Represent.

Given the result above, sketch a graph of the current through the resistor when the capacitor is charging. Describe how the graph would change if you were to increase the resistance of the circuit. Give a physical explanation for why you observe this change.
🔗
🔗
🔗
🔗
PrevTopNext