Why do incandescent lamps(filament bulbs) glow when electricity flows through them?
[5 MARKS]
Why do incandescent lamps(filament bulbs) glow when electricity flows through them?
[5 MARKS]
Explanation: 5 Marks
Electricity flows better through some materials than others. Metals that let electricity flow easily are good conductors that have low electrical resistance; plastic, wood, and other insulators have a high resistance. Some metals are better conductors than others: silver is better than gold, gold is better than copper, and copper is better than aluminium. Not all conductors are metals, however. Carbon is a good conductor and it has little in common with most metals.
Now suppose you could make a conductor that's both short and thin and pass electricity through it. Fashion it just right and it'll have enough resistance to make the current work hard and not so much that it stops the current completely. Switch on the electric current and your conductor (which is usually called a filament) will heat up. Use enough electricity and the filament will heat up so much that it'll glow red or white hot and give off light. That's the basic idea behind the incandescent electric light.
Explanation: 5 Marks
Electricity flows better through some materials than others. Metals that let electricity flow easily are good conductors that have low electrical resistance; plastic, wood, and other insulators have a high resistance. Some metals are better conductors than others: silver is better than gold, gold is better than copper, and copper is better than aluminium. Not all conductors are metals, however. Carbon is a good conductor and it has little in common with most metals.
Now suppose you could make a conductor that's both short and thin and pass electricity through it. Fashion it just right and it'll have enough resistance to make the current work hard and not so much that it stops the current completely. Switch on the electric current and your conductor (which is usually called a filament) will heat up. Use enough electricity and the filament will heat up so much that it'll glow red or white hot and give off light. That's the basic idea behind the incandescent electric light.
