Electrical Resistance
Electrical Resistance is how much a wire or material fights the flow of electric current through it.
Water flows through a wide pipe faster than through a narrow one. A straw has high resistance — it blocks the flow. A garden hose has low resistance — water moves through it easily. Electrical resistance works the same way in a wire.
Explaining electrical resistance by grade level
A wire carries power to things that need it. Some wires make it harder for power to flow. When a wire gets hot, it fights the flow even more. A hot wire lets less power through than a cool one.
Projects that explore electrical resistance
Temperature changes how much a material fights the flow of electric current. In this experiment, resistance rises steadily as the wire heats up, while the current drops. Hotter copper atoms vibrate more, making it harder for current to pass through the wire.
Every material fights the flow of electric current by some amount, and an ohm meter lets you measure that resistance directly. Tracking resistance at each 10°C temperature step reveals a clear pattern: as the wire gets hotter, its resistance rises and the current drops. The same wire carries less current at higher temperatures because the material fights the flow of electrons more strongly.