DC Circuits with Resistors and Capacitors.
A) To study the behavior of a simple circuit consisting of capacitors and resistors.
B) To measure the equivalent capacitance of series and parallel combinations of.
capacitors.
Procedure:.
We started off with Part A which dealt with the charging and discharging of capacitors. We setup the circuit as seen in Figure 1a with S1 being open in order to measure the time constant for discharging capacitors. The power supply(30V) was connected across C2(terminals P4 and P5) and also connected was the electrometer-voltmeter across the resistor R2(terminals P3, P4). The timer was then switched on the exact time S1 was switched to P2 and readings were then taken every 10 seconds for the first minute, then every 20 seconds up to the third minute, then every 40 seconds up to the seventh minute.
In step 3 of this procedure we were again studying the charging of the capacitor, and the circuit was setup up according to figure 3. With E=30V,R=1x10^8 Ù,C2=1x10^-6f and S1 being open while the power supply was across P1-P2. The voltmeter was set to read VR and S1 and P1 were connected to one another and VR was then measured as the same procedure as in step 1 above.
In part B of this experiment we were to do steps 4 and 5 which was to measure the series and parallel combination of capacitors.
In part 4 of the experiment S1 was set at open and the circuit was arranged so that the capacitors C1 and C3 were in a series. Thirty volts were then applied across the series arrangement, P3 to P5 then the power was disconnected. The voltage was then measured across C1, V1, across C3, V2, and across P3, to P5, V. This procedure was then repeated using C2 instead of C3.
Finally for part 5 we connected S2 to C1 and S3 to C2 while having S1 open. Thirty volts were again applied across P4 to P5 and again the power supply was removed and the voltage was measured V1(P4-P5). The S1 switch was then turned to the P2 position making points P2, P3, P5 equivalent and then the new voltage measurement was taken V2(P4-P5).
