- Eve Robles
5 Common Myths About Electricity
Electricity Travels At The Speed Of Light
Most people associate electricity with lightning at a very early age, and thus comes the misconception that electrons and electricity move at—or close to—the speed of light. Although it is true that the electromagnetic wave of energy travels along a conductor at 50 percent to 99 percent of the speed of light, it is important to realize that the actual electrons move very slowly, no more than a few centimeters per second.
Power Lines Are Insulated
Most of the wires and cables we come in contact with—device chargers, lamp and appliance power cords, jumper cables—are heavily insulated with rubber or plastic. An innocent assumption to make is that overhead power lines are also insulated. Birds can stand on them, so they have to be harmless, right? Wrong!
The only reason birds don’t get electrocuted is because they don’t touch the ground while on the cable; as a result, there is no charge imbalance and no flow of electrons. Since insulation is very expensive, most overhead power lines are always live and can have currents anywhere from 1,000 volts to a shocking 700,000 volts running through them.
Static Electricity Is Different From Outlet Electricity
Static electricity can be fun to play with—rub your feet on a carpet for a little bit, and then go shake someone’s hand; make a new friend! Whether they appreciate your type of humor or not, chances are, they think that static electricity is different from the current that powers our daily lives. However, the only difference between flowing and static electricity is that one is a constant flow, while the other is an instantaneous equalization.
The current in wall outlets is an electromagnetic energy field that is waiting to be transferred via electrons in a conductor, such as a power cable. Once plugged in, the current is constant and remains constant until the cable is unplugged. On the other hand, static electricity happens when two conductors with different charges come close to each other. When the space between them—known as an insulating gap—gets small enough, the charge bridges the gap, causing the arc of electricity as the two charges equalize.
Wooden And Rubber Objects Are Good Insulators
When doing any sort of electrical work around the house, the first approach of most people is to take off rings or jewelry and to put on rubber gloves and shoes. Although these are good first steps, they are insufficient to prevent an accident. Unless explicitly stated otherwise, most common household items are conductors to some degree, rather than insulators.
Pure rubber is an excellent insulator; however, most rubber shoes, gloves, and other goods are rarely pure rubber, having been mixed with additives for strength and durability. Even wood can be a conductor in the right conditions.
Low Voltage Shocks Are Not Dangerous
Wall outlets and forks are a huge concern for parents raising small children, but they don’t hesitate to hand their kids batteries to place into their toys. Only high voltages are dangerous, right? Wrong!
Rather than voltage, it is the current of electricity (measured in amperes) that has the power to kill and harm. In the right conditions, even a 12 V battery—such as a car battery—can cause some serious harm, and in extreme cases, death.