Electricity: Taste the Power!

Can you taste electricity? Maybe not, but it feels as if you can.

You will need:

• 9-volt battery
• Snap connector for battery terminals
• Multimeter

Procedure

1. Moisten your tongue and touch the tip of it to the metal terminals of a 9-volt battery. The sudden sharp tingle that you feel is caused by electricity flowing from one terminal of the battery, through the moisture on and in your tongue, to the other terminal. Because the skin of your tongue is very thin (it’s actually a mucus membrane) and the nerves are close to the surface, you can feel the electricity very easily.
2. Now stick out your tongue, dry the tip of it very thoroughly with a tissue, and repeat the experiment without allowing your tongue to become moist again. You should feel less of a tingle.

• What’s happening here? We’re going to need a multimeter to find out.

Fundamentals

We measure distance in miles or kilometers, weight in pounds or kilograms, temperature in Fahrenheit or Centigrade—and electrical resistance in ohms. The ohm is an international unit.

The Greek omega symbol (Ω) is used to indicate ohms. Letter K (or alternatively, KΩ) means a kilohm, which is 1,000 ohms. Letter M (or MΩ)
means a megohm, which is 1,000,000 ohms.

A material that has very high resistance to electricity is known as an insulator. Most plastics, including the colored sheaths around wires, are insulators.
A material with very low resistance is a conductor. Metals such as copper, aluminum, silver, and gold are excellent conductors.

Procedure

We’re going to use the meter to discover the electrical resistance of your
tongue.

• Plug the black probe into the COM port on your multimeter.
• Plug the red probe into the VΩmA port.

• Switch on your multimeter, and set the dial to resistance mode.
• Resistance is measured in ohms, indicated by the Ω symbol.
• Most multimeters are not autoranging, meaning you will need to set the correct range for the resistance you expect to measure. If you’re not sure, start with the highest setting.

• Touch the probes to your tongue, about an inch apart..

• It doesn’t matter which probe goes where; resistance is non-directional.
• If your multimeter reads close to zero, the range is set too high for a good measurement. Turn the dial to a lower setting.
• If you set the range too low, the multimeter simply reads 1 or OL, indicating that it is overloaded or out of range. This won’t hurt the multimeter, but we need to set the dial to a higher range.

• The reading should be around 50k.

• Now put aside the probes, stick out your tongue, and use a tissue to dry it very carefully and thoroughly. Without allowing your tongue to become moist again, repeat the test, and the reading should be higher.
• Finally, press the probes against the skin of your hand or arm: you may get no reading at all, until you moisten your skin.

Moisten your skin before trying to measure its resistance. You should find that the resistance goes up as you move
the meter probes farther apart. The resistance is proportional to the distance.

• A 9-volt battery contains chemicals that liberate electrons (particles of electricity), which want to flow from one terminal to the other as a result of a chemical reaction inside it.
• Electrons flow more easily through some substances (such as a moist tongue) than others (such as a dry tongue).