Series and Parallel Capacitors (5C30.42)

Description:

Two capacitors mounted on a board which can be used individually, in series, or in parallel. After a combination has been charged to 1.5 V, it is discharged through a galvanometer, and the amount of charge the combination held is reflected in the displacement in the galvanometer.

Procedure or Operation Notes:

Not shown in the picture above is a battery (and one switch) on the left side, and a galvanometer (and another switch) on the right.

NEVER press both switches at the same time. The galvanometer is very sensitive and the current from a battery can easily damage it.

1) Start with only one capacitor connected as shown:

Momentarily press the Charge switch to charge the capacitor.

2) Release the Charge switch and then press the Discharge switch. The galvanometer needle will jump to approximately 50mA.

3) Repeat for the other single capacitor connected individually to the battery. The galvanometer will again jump close to 50mA but the two capacitors can vary by as much as 20% from the value printed on the side (4 μF).

4) Connect both capacitors in parallel as shown:

The galvanometer will read close to 100 mA but the deflection is based on the current which is based on the sum of both capacitors (not necessarily twice either individual capacitance).

5) Connect both capacitors in series as shown:

The galvanometer will read close to 25 mA (half the value of a single capacitor).