Voltage & Current

Project Number: 17

Description: Build the circuit shown. Set the meter (M6) to the 5V setting. Push the switch (S2) to connect the meter to the battery and measure its voltage.

Snappy: Electricity is the movement of subatomic charged particles (called electrons) through a material due to electrical pressure across the material, such as from a battery. The electrical pressure exerted by a battery or other power source is called voltage and is measured in volts (V). Notice the "+" and "-" signs on the battery. These indicate which direction the battery will "pump" the electricity. Circuits need the right voltage to work properly. For example, if the voltage to a light bulb is too low then the bulb won't turn on; if too high then the bulb will overheat and burn out. The electric current is a measure of how fast electricity is flowing in a wire, just as the water current describes how fast water is flowing in a pipe. It is expressed in amperes (A) or milliamps (mA, 1/1000 of an ampere). The "power" of electricity is a measure of how fast energy is moving through a wire. It is a combination of the voltage and current (Power = Voltage x Current). It is expressed in watts (W).