PHYSICS · Multi-part · AP · Physics 2: Algebra-based · Electric Circuits · Electric Circuits
Problem
A circuit consists of a battery of emf 12 V, a resistor R=1.2kΩ, and a network of three capacitors connected between points X and Y as described below.
• Capacitor C1=5μF is connected directly between X and Y.
• Capacitor C2=4μF is connected in series with capacitor C3=12μF. This series combination is connected between X and Y in parallel with C1.
All capacitors are initially uncharged.
(a) Calculate the equivalent capacitance of the entire capacitor network between X and Y. Show all steps clearly.
(b) The switch is closed at t=0, connecting the network, the resistor, and the battery in series. Determine the time constant τ for the charging process. Express your answer with appropriate units.
(c) At time t=τ, determine the potential difference across the entire capacitor network. Justify your answer using the defining property of the time constant in an RC circuit.