HOW DO LIGHT BULBS LIGHT UP?
The filament inside a light bulb is much thinner than the wires that lead up to the bulb. The charges flow slowly in thick wires, but they must flow fast in the thin filament. Charges experience a kind of “electrical friction”, and when they flow faster, more heat appears. This friction experienced by the fast charges heats up the filament. The same kind of “friction” heats up all wires, but the charges flow slowly in thick wires, so this heating is usually not enough to even notice. The same kind of friction heats up the wires inside of toasters and electric heaters. In that case, the heating isn’t enough to make the wires glow WHITE HOT like a light bulb filament. Instead they just glow red or orange.
