Semiconductors are normally very poor conductors of electricity. But with the addition of tiny amounts of other elements, which provide carriers for electric current, they can become good conductors.

But they are poor conductors. So what happens is a lot of energy goes into heating the ground or heating the ionosphere. So when I'm going to send energy from Long Island to Paris, I'm going to ...

Or this salty water. Now, the outside of electric wires are usually covered in plastic because it’s a very poor conductor. It hardly conducts any electricity at all, so we can say it’s an ...

But because cardboard is a poor conductor, the heat energy from your finger is barely transferred to the cardboard. Since the motion of molecules in your skin stays about the same, your skin feels ...