Energy and Power in Circuits

Resistors get hot when an electric current passes through them

• When there is an electric current in a resistor there is an energy transfer which heats the resistor
• This heating effect increases the resistors resistance- so less current will flow, or a greater voltage will be needed to produce the same current
• This heating effect can cause components in the circuit to melt- which means the circuit will stop working or not work properly. Fuses use this effect to protect circuits- they melt and break the circuit if the current gets too high
• The heating effect of an electric current can have other advanates. For example, its ace if you want to heat something. Toasters contain a coil of wire with a really high resistance. When acurrent passes through the coil its temperature increases so much that it glows and gives off infra red…