Measuring the time rate of decay for an RC circuit Set up a RC circuit and measu
ID: 1568599 • Letter: M
Question
Measuring the time rate of decay for an RC circuit Set up a RC circuit and measure the voltage discharge for different time values. Plot V against time on a semi-log graph paper, and determine the decay time constant and the capacitance of the capacitor you have used. You should measure the resistance of the resistor you use. (Choose a suitable capacitor and resistor. If you are using the stop watch method you should aim for R and C values that gives you a reasonable decay time (about 20-60 seconds). You should have at least six data points: spanning a voltage decay range of about 10. You should make a sketch, enter all the components/equipment used, data entered in a neat table, a brief explanation of what you are doing. Compare your measured values with calculated values (for time constant and C).Explanation / Answer
For any RC Circuit for Voltage Discharge,
V(t) = V0 * e-t/RC,
where V0 = Initial Voltage
R = Equivalent resistance
C = Equivalent Capacitance
RC = Time Constant of the Circuit
t = Time in sec
By Varying the V0 and keeping R and C Constant, the Time Rate of Decay will be Directly proportional to the Voltage V0 because the Time Constant, RC is constant.