RC time constant of a capacitor - Essay Example

At the same time that happens, the upper plate receives electrons making it of a positive charge (Platt). This process is not instantaneous; it takes time. At the beginning, current is high and begins to decrease as charge accumulates on the plates. At the beginning there is no voltage across capacitor but increases as charging continuous. capacitor voltage Vc, increases towards Vb but asymptotically. During the charging and discharging process, exponential laws as below are adhered to Using the requirements provided the circuit was connected as shown above using a 470µF and 80,000Ὠ resistor.

Measurements using the multi-meter was taken for time intervals of 10seconds. The results of Vc, Vemf-Vc, Ln(Vemf – Vc/Vemf) were recorded in a table 1. At this moment the capacitor was fully charged. The value of voltage across V0 was recorded. The second part of the experiment began by undoing the switch from each procedure above and the timing process was done and table 2 was filled with relevant data Vc, Ln(Vc/V0), and time in table 2. Logger pro was opened and voltage adjusted to zero.

Time constant was set to 150seconds. Capacitor was recharged holding the voltage probe across capacitor. Switch was flipped to B and hit collect on logger pro. Natural exponent function was selected on the logger pro. Data obtained was then recorded. The practical objective were met and the practical was successful. Data used for calculation was obtained from finding the average of the data obtained from trials 1 and 2. When a capacitor is connected to a battery, it charges and the rate at which it happens is dependent on the time constant.

By opening the switch, the capacitor discharges. The theoretical value of the time constant differ from the practical value obtained after plotting the graph, finding gradient and calculating for time constant. This is due to human measurement errors, faulty components, and faulty meters. Timing in this experiment is the