Combination of capacitors in series
Wire the circuit as shown in the following figure. for a resistance R = 3.8MΩ . and two capacitors of C1 =6 μF and C2=3 μF

Note :
Start counting the time using a stopwatch simultaneously when powering the circuit with a DC voltage source E =8V.
Read the voltage across the capacitor each 05 seconds and record the values in the following table
t(s) | 00 | 05 | 10 | 15 | 20 | 25 | 30 | 35 | 40 | 45 | 50 | 55 |
Uc(V) | 0 | 2.6 | 4.10 | 4.80 | 5.42 | 5.70 | 6.01 | 6.1 | 6.1 | 6.1 | 6.1 | 6.10 |
Method :
a- On graph paper, plot the voltage Uc= f(t)
b- Plot the tangent to the origin point and determine the time constant, τ = RC; the abscissa of the point of intersection of this tangent with the load limit voltage
c- From the time constant ensure the value of C.
Capacitors in Series
The equivalent one of two capacitors in Series is given by
Compare this value to the equivalent one of two capacitors in Series
Extra :
In this graph we found τ is 11.8s which is close to the calculated one τ = RC = 11.4s
