Wires and Circuits Flashcards
How do conductors and insulators work?
For metal, it is the delocalized electrons involved in metallic bonding that allow metals to conduct electricity. The delocalized electrons are free to flow through the metal and so carry a current.
Ionic solutions are also able to conduct electricity because they have mobile charge-carrying particles.
Insulating materials do not contain free electrons and so current is unable to flow.
How wires or leads work in a circuit?
Wires or leads are used to carry the current around a circuit between the components.
This copper lead is made from thin wires twisted together to make the lead more flexible.
Copper is used as it is a very good conductor of electricity.
The lead is covered with a plastic sleeve, which prevents a short circuit if the lead touches other bare wires.
What is a short circuit?
Current will always pass along the path of least resistance. The resistance of the wires in a circuit is low compared to the resistance of components, such as bulbs.
If current can flow along a path without passing through the components this part of the circuit is called a short circuit.
What are the 2 ways to represent current flow?
Before the discovery of the electron, scientists assumed that current was due to positively-charged particles moving from the positive terminal around a circuit to the negative terminal. This way of representing the direction of current is called conventional current.
It is now know that charge is carried by electrons, flowing from the negative terminal to the positive terminal. This is called electron flow.
