Experiment Description

Experiment

Experiment E03    Measuring Capacitance Using a Reed Switch

Objectives
  • Learn the use and the working principle of a reed switch
  • Study how a reed switch can be used to measure capacitance
  • Investigate the series and parallel combinations of capacitors
  • Study the discharging process using a CRO
Description
In this activity, you will use a reed switch to measure capacitance. The reed switch is driven by a signal generator of known frequencies.

In Experiment 1, a capacitor is quickly charged and discharged using a high frequency reed switch. The capacitance is calculated from the average discharging current.

In Experiment 2, you will verify the equation for series combination of two capacitors. The combined capacitance is measured by the reed switch circuit.

In Experiment 3, you will verify the equation for parallel combination of two capacitors. The combined capacitance is measured by the reed switch circuit.
Apparatus
capacitor (2.2 mF) [1]
variable resistor (0 - 10 kOhm) [1]
milliammeter (100 mA base meter) [1]
battery box with 3 dry cells [1]
signal generator [1]
reed switch [1]
multimeter [1]
Experiment