How to Administer Electrical Currents
- 1). Turn on the multimeter. Switch it to "Voltage."
- 2). Find a source of charge. A source of charge can be anything that has a potential difference, or voltage, between it and another point. You can measure this with the multimeter when it is set to "Voltage" by holding the tip of of each probe against the two points you want to measure the voltage between. Try rubbing your shoes on the carpet and measure the voltage between your hand and the carpet. There are many sources of charge available, such as batteries, transformers and household electricity. You can test the voltage between two points of a battery, but never use the multimeter with the household electricity.
- 3). Find a conductor. A current will flow through different materials at different rates. Turn the multimeter to "Ohms." This will allow you to measure how easily a current will flow between two points. Touch each probe at each end of the material you want to test to measure the resistance. The lower the number, the easier current will flow through the material. It is this property that allows us to control the current passing through an object. Using Ohm's law, if the voltage of the current source remains the same, a higher resistance will reduce the current flowing through the object. Copper wire is a good conductor of current; wood is a bad conductor.
- 4). Administer the current. Place a conductor of low resistance between the two points of potential difference. It is best to use a small battery for this test. You are now controlling the current flow between these two points. Switch the multimeter to mA and measure the current between the two points of potential difference. Now measure the current between the halfway point of your conductor and the source of potential difference. This will be a lower number. This is due to the resistance of the conductor. If you want to reduce the current, use a conductor with a higher resistance.
