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Electricity: Top 10 Questions

January 2013

Thanks to John Gardner, Professor of Mechanical and Biomedical Engineering, Boise State University; and Kip Sikes, Operation Analysis and Development Manager, Idaho Power for the answers.

1: What amount of electricity does the average person in the U.S. use in a week?

We think of this in terms of horsepower. The average household uses 1.6 horses every second. It's like a constant horse riding around. That's how much electricity we are using all the time. (From Joel at Dalton Gardens Elementary School in Dalton Gardens)

2: How do clouds get electricity?

Lightning is a natural phenomenon that happens as the clouds move through the air. The atoms and molecules in the air and the water in the clouds have free electrons that get exchanged as the clouds move through the atmosphere. The electrons build up on the clouds and need a place to go. They'll usually go to the closest spot that's of a different charge level. That's usually why lightning will hit a tree. It happens in the atmosphere as a course of everyday events. (From Ryan at Dalton Gardens Elementary School in Dalton Gardens)

3: How does electricity travel?

There is more than one way electricity travels. Normally, we think of it traveling through a conductor, or a wire, where the electrons bounce and push each other through. Electricity can also be stored. A battery can be used for this. Overall, for electricity to flow, a circuit is needed that allows for a complete connection circle all the way around to the source. (From Megan at Valley View Elementary School in Boise)

4: When was electricity discovered?

We're not sure. A lot of understanding of electricity came about in Europe in the 1700s. Many of the scientists who made some of the discoveries have names that are associated with electric terminology. A volt came from the scientist Volta, and amps came from the scientist Ampere. It was over a period of hundreds of years that people studied or investigated electricity. In the 1800s, Thomas Edison created a grid that allowed the electricity to be sold to the people of New York City. (From Charlotte at Valley View Elementary School in Boise)

5: How does electricity end up in everyone's home?

Electricity is produced by a generator that has wires in it. It gets to your home through this series of wires, called a grid, that run between states or throughout your region. (From Tyler at Cynthia Mann Elementary School in Boise)

6: How fast can electricity travel through water?

If it's pure water, electricity won't travel through it at all. It can't, because the water acts like an insulator. Small impurities in the water, like tap or river water, conduct electricity. Impurities, like salt, are really good at conducting electricity. Impurities will allow more and more electricity to move through the water. When electricity flows, it flows at a speed close to the speed of light. This is very, very fast. (From Yoshi at Valley View Elementary School in Boise)

7: Why is it that when you rub your feet across the carpet, you make electricity?

It has to do with static electricity. When you rub your feet across the carpet, your shoes act as insulators. As electrons build up on your body, you get a charge of electrons that's different than somebody else. So, the more you rub, the more electrons transfer to you that you can't get off until you reach out and touch someone. Zap! That zap that you feel is a little mini lightning bolt and that's why it hurts. (From Owen at Dalton Gardens Elementary School in Dalton Gardens)

8: How does tidal power work?

Tidal power is similar to hydroelectric power that we are more familiar with in Idaho. The water is held up by dams and it gets higher and higher above the level of the river. We use gravity to move that water down to the level of the river. While it's on its way through, it spins a turbine that generates power. With tidal power, sometimes the tides will rise and fill the water behind a dam. They'll close the dam off, and then it looks like a hydro dam. Sometimes, if the tides are coming though a smaller area, like a river, they'll put propellers underwater, anchored to the floor of the river. The tide will move past the propellers and the flowing water moves the propellers, spinning a turbine that turns the generator. (From Kendall at Valley View Elementary School in Boise)

9: What creates the electricity in solar panels and lightning?

Solar panels are basically made of sand or silicon. As the sunlight hits them, the electrons get excited. Gates are used to let the electrons out in just one direction, which creates the current. The electrons then bounce out of the solar panels. Lightning is actually static electricity. As clouds rub against the atmosphere, charges build up that are different between the cloud and the earth. Once there's enough difference in the electrons, the positive and negative charges, the air is ionized. This creates that big zap that allows the electrons to go through the air and down to the ground to balance out the charges again. (From Ryan at Cynthia Mann Elementary School in Boise)

10: What properties of metal and bone make them great conductors of electricity?

Free electrons make a good conductor. A good conductor is something that is made of atoms that have a lot of electrons that can move from atom to atom without a lot of resistance, meaning they can move easily. If you have a piece of metal or bone, it doesn't mean electrons are moving through them constantly. It takes a difference in voltage to make them move. If you can push the electrons and they can move easily, that's what makes a good conductor. Something that's an insulator is where the electrons are bound very tightly together and don't move. Even if you push on the electrons, they are going to stay in place. (From Moses at Valley View Elementary School in Boise)


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