Heat

Wasted Energy

Recall that resistance is caused by collisions __between the __electrons and ions in the wire. These collisions transfer some of the energy into thermal energy as the electric current is doing work against the electrical resistance. The thermal energy is dissipated to the surroundings as heat.

Resistance

Efficiency

We can increase the efficiency of the circuit a few different ways:

• Have a larger wire: Larger wires are able to carry more current and therefore reduce the resistance
• Superconductivity: Cool the wires until they are very cold. This means that the ions will be vibrating less and as such there will be fewer collisions

Heating Effect

The heating effect can be advantageous. For example, a filament bulb gives out light because the filament__ glows__ white hot due to the resistance. Fuses (mentioned in more detail later on) also work due to the heating effect.

There are, of course, disadvantages. For example, if a circuit gets too hot then it can break and no longer work. There is also a__ fire risk__ if the components or wires get to hot.