How Everything Works
How Everything Works How Everything Works

Question 1214

It is difficult for me to understand current flowing from a battery through a circuit. A battery has both a positive end and a negative end. Which direction does the current flow? — SK
When you connect a battery in a circuit, negatively charged electrons flow away from the battery's negative end and they return toward the battery's positive end. The battery then pumps the electrons back to its negatively charged end and they begin the journey all over again (hence the name "circuit"). But because the electrons have a negative charge, current does not flow in their direction. Instead, current is defined as flowing in the direction of positive charge flow. In the present case, current flows from the battery's positive end, through the circuit, and back to the battery's negative end. Current is thus flowing in the direction opposite to the direction of electron movement! If you want to know which way current is flowing, you can normally find the direction in which electrons are flowing and then reverse it. Life for physicists and electrical engineers would be so much simpler if Benjamin Franklin hadn't made an unfortunate choice that gave electrons—the principal carriers of electricity—a negative electric charge. We have been living with the consequences of that choice ever since.

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