RC Circuit,Charge Buildup, Decay in Capacitors

Lab Day 19 4/30/15 : RC Circuit Charge Buildup and decay in Capacitors

Purpose: To analyze the idea of capacitors and the charge buildup and discharging of capacitors in a circuit. We will look at the different types of RC circuits and do quantitative and qualitative analysis of the relationships between charging and discharging transient RC conditions.

Capacitors Charging/Discharging

We started by connecting capacitors in series and measured the capacitance using batteries, a light bulb, and a capacitor. We analyze the charge build up caused by a capacitor and how a light bulb would light up when it is connected after charging and how it will gradually dim out as it is discharging. We found that as the capacitance increases, it would take a longer time for it to charge up.

Experiment: Exponential nature of charging and discharging of a capacitor

Charging of capacitor

The results show in our graph the charging and discharging of the capacitors. We get an exponential function that is increasing or decreasing. This also shows that there is a relationship in which the voltage increases exponentially while charging and decreases exponentially when discharging.

Discharging of capacitor

Here are the work for the experiment of charging and discharging for analysis.

RC Circuit Problem

Next we look at a RC circuit problem where we find the max charge the capacitor would obtain, the voltage drop, and the time using the equations derived previously shown in the calculations below.

Conclusion: We found that there is a charge buildup and a discharge in capacitors exponentially based on experiment. We found that when two capacitors are connected, the charge and the summation of the capacitance if used to find the voltage. In fact voltage, current in respect to time is identified when analyzing the charging and discharging of a capacitor. The time constant is used in relationship to the rate of the potential of a capacitor.