Home >> Science & Nature >> Science

DIY Kit Resistance Measurement

There are number of macroscopic electrical quantities that are commonly measured in circuits and these include voltage (potential energy per unit charge), current (a scaled electron velocity), and resistance (a measure of how much electrons scatter). Resistance is most commonly measured using a multimeter but there are other ways to measure the quantity. A simple resistance measurement kit consists of a voltmeter (used to measure voltage) and an ammeter (used to measure current). By measuring both quantities simultaneously, the resistance can be obtained from Ohms law.

Things You'll Need

Ammeter
Voltmeter

Instructions

- 1
  Place the ammeter in series with the circuit whose resistance needs to be measured. Some ammeters have a range setting. If possible set this to auto-range otherwise set it to a value below the applied current.
- 2
  Place the voltmeter in parallel with the component whose resistance needs to be measured. The component may be a resistor or another electrical device such as transistor. The voltmeter may also have a range setting. Set the range setting to auto-range if possible otherwise set it to below the applied voltage.
- 3
  Switch on the electrical circuit. The voltmeter and ammeter should display readings. Write down the value of voltage in Volts and the value of current in Amps. Ohms law states: R= V / I. R is the resistance, V is the voltage, and I is the current. Plug the values of voltage and current into the equation. For example, if 10 Volts were measured across a resistor, and the current flowing through the circuit is 2 Amps, then the resistance is: R= 10 / 2 = 5 Ohms.

Science