PHYSICS · Multi-part · A Level · Physics · Fields and their consequences · Fields and their consequences
Problem
A circuit consists of a 12V ideal battery, a switch, a resistor network, and a capacitor network as described below.
• Resistors: Two identical 150Ω resistors are connected in parallel. This parallel combination is in series with a single 100Ω resistor.
• Capacitors: A 6.0μF capacitor and a 3.0μF capacitor are connected in parallel. The parallel pair is connected in series with a 2.0μF capacitor.
Initially the switch is open and all capacitors are uncharged. At t=0 the switch is closed, connecting the battery to the network.
(a) Calculate the equivalent capacitance of the entire capacitor network. Show your steps clearly.
(b) Calculate the equivalent resistance of the entire resistor network.
(c) Determine the numerical value of the characteristic time that describes how quickly charge accumulates on the capacitors once the switch is closed. Include units with your answer.
(d) The two 150Ω resistors are now rewired so that they are in series with each other (still in series with the 100Ω resistor). Without doing additional arithmetic, state whether the characteristic time found in part (c) would increase, decrease, or stay the same, and briefly justify your choice.