You Might Also Like
You are ready for bed and want to walk up the stairs to the bedroom. At the bottom you flick a switch to turn on the stairway lights and when you get to the top there is another switch to turn the same lights off. It's thanks to three-way switches that you can do this. Learn all about these special switches by taking this quiz.
Solar panels sit atop buildings, homes and tents, and power any number of gadgets and appliances -- including refrigerators. But can the sun still power a fridge without the panels?