The Mouse - Cheese Analogy for Electricity
All matter is made up of positive charges and negative charges. The positives have mass and are not usually free to move. The negatives have no mass and are free to move through some materials (conductors). Negative charges are attracted to positive charges the same way mice are attracted to cheese. Any time there is a natural attraction between two things we can use it to make the objects do work. The negative charges (mice) will gladly do work in order to get to the positive charges (cheese).
- Voltage:
- The amount of work that each charge (mouse) will do as it goes through the circuit. Can also be thought of as the amount of push on the charges or how hungry the mice are.
- Current:
- The number of charges (mice) passing a point per second. The rate of flow of charges.
- Resistance:
- The opposition to the flow of charge. Any appliance that asks the charge (mouse) to do work will slow it down.
- Electromagnetism:
- Whenever a charge (mouse) moves it creates a magnetic field. The faster it moves, the stronger the field. The field created by one moving charge can add/subtract with another field.
This set up has a voltage (desire on the part of the mouse) but no current flows because there is no conductive path. It has the ability to do work but no way to get there.
The Mouse Cheese Circuit
The mouse (electron) will gladly do work to get to the cheese (proton). Now that it has a path to allow the mouse to move, work can get done.
The Mouse Cheese Battery (cell)
The battery goes "dead" when all the negative charges make it through the
circuit and get to the positive charges.
Types of Cells and Batteries
 |
D cell 1.5 volts |
 |
AA cell 1.5 volts |
 |
lantern battery 6 volts hungrier mice
slightly flawed: the lantern battery would also have many more mice than the D cell, but that is not related to it being 6volts |
Mice Cheese/Cat |
wall outlet 120 volts VERY HUNGRY mice! In reality, the one side of the outlet would change from cheese to cat 60 times a second. That's why we call it alternating current (AC) because the mice would change direction 60 times a second. |
As we look at electrical safety, the mice (electrons) in the D-cell are not hungry enough to pass through your body to get to the other side of the battery. This is why you can touch both ends without any damage or even feeling. The mice in a nine volt battery are not hungry enough to pass through dry skin to get to the other side of the battery but if you touch it to your wet tongue you will feel the mice (electrons) running through it to get to the cheese (positive) side of the battery. If you touch just the mouse side of an electrical outlet, you won't feel anything as the mice have no way to sense the cheese or the cat on the other side of the outlet. However, if you touch the mouse side and the cheese / cat side at the same time the mice will race to the cheese side through you and run from the cat through you. The experience can be quite deadly. The body has this reflex that when mice run through muscles, the muscle contracts. If the muscle is the heart, no beating occurs while the mice run through it. In fact, if you were to only touch the Cheese / Cat side of the outlet, the cheese would attract some of the mice (electrons) that make up your body out of your body then the cat would scare them back into your body and many would run out your feet to the ground, then back up to get the cheese, then back down to avoid the cat. This would happen 60 times a second until you let go of the cheese cat side of the outlet. Since this Cheese / Cat side of the outlet (not always on the right side) is deadly all by itself, this side of the outlet is often called the "HOT" side.
Any aspect of electricity can be put in terms of the mouse cheese analogy. If you get stuck on a topic in electricity, try to relate it to this analogy and expand on it.
