Question #88df0
1 Answer
Electric current is formed by driving electrons inside a conductor (such as a wire) to flow in one direction.
Explanation:
Electrons are already moving around in a wire (made up of metal), but there are as many of them moving to the left and as to the right. Effectively produces no net electric current.
To drive the electron to effectively move in same the direction after a lot of bouncing around, you need an energy source, such as a battery that has two terminals. The positive terminal attractive the electrons toward it while the negative terminal pushes electrons toward the positive terminal. Electrons flowing from negative terminal to the positive terminal is an electric current. You may think the terminal eventually run out of electrons. No, because the electron sort of go through the battery and emerge on the negative terminal again.
Electrons are negative, you could also think of positive charges flowing from positive terminal to the negative terminal. That is what people conventionally mean when they are talking about electric current.
Battery is only one way to drive a current. You can use a generator and even magnet to drive the current, as long as you produce a voltage difference.
The positive terminal is said to have high voltage than the negative terminal. It is the voltage difference that drives the current, i.e., drive electrons to the positive terminal or positive charges to the negative terminal. If the voltage difference drops to zero, the current flow will stop. That's what happen to a dead battery when it can no longer sustain a voltage difference.
BTW, you can create the voltage difference in a wire loop using a magnet.
