Answer to Question #72125 in Electric Circuits for jojo

Question

(a) Here is the information about the circuit.
Capacitor = 100 nF
Resistor = 47 kΩ
Supply voltage = 5 V
Charging characteristic for a series capacitive circuit: v(1-e^-t/rc)
where T  CR and is called the time constant.
 Investigate what the other terms in this expression mean.
 Calculate the time constant for the circuit.
 Use a spreadsheet to plot the charging curve over the range 0 to 20 ms (milliseconds).
 Investigate the meaning of ‘time constant’ and from your graph estimate a value. Compare this with your calculated one.
 Differentiate the charging equation and find the rate of change of voltage at 6 ms.
 From your graph measure the gradient at 6 ms and compare this with the calculated value.


(b) Now investigate the discharging characteristic of the circuit but with a 22 kΩ resistor fitted.
 Calculate and estimate the rate of change of voltage when t = T.