You reach for a switch and click – your lights, fan, washing machine, toaster, television, laptop, hairdryer, and mobile phone charger can be turned on in a blink of an eye. What makes this possible?
Power stations turn one kind of energy (or power) into another. Hydroelectric power stations turn the energy of falling water into electricity. Huge dams are built at lakes and rivers that channel billions of gallons of water through turbines. As water rush down through giant pipes, it will hit against metal blades of the turbine and make it spin, just like a revolving door spinning when people push through it. This turbine will in turn spin a magnetic wheel, producing electric current that flows into wire cables. The electric current will then flow into a transformer to give the current a boost so that it could travel further along the power lines that you see from pylon to pylon.
These thick power lines will eventually reach your home and be dispersed into many smaller wires that spread out all over your place and eventually reaching your power sockets and switches. Electric current zips along at three hundred thousand kilometers per second. This means that the electricity generated in as far up north in Perlis and as far down south in Johor will reach Klang Valley faster than you can blink!
Electric eels are a kind of fish that can generate up to five hundred volts of electricity. Such a shock could be deadly for an adult human! But these fish use their electricity to stun or kill other animals for food. Another interesting fact is that a single bolt of lightning has enough energy in it to keep a lightbulb lit nonstop for three months! Imagine if you can store all the lightning around your home, your electricity bill will be zero!
Experiment: To generate electricity from a lemon
Materials:
Steps:
1. Gently squeeze a lemon evenly.
2. Poke in a 5¢ coin and a 1¢ coin at two ends of the lemon halfway through.
3. Separately attach the coins to a LED using a wire with clips.
4. Watch the LED light up.
Fact:
Lemon juice is an electrolyte – which means it can conduct electrons from one type of metal to another type of metal. This forms a low-powered electric circuit.
Glossary of terms:
Turbine [tur -bayn ] machines having a rotor, usually with blades, driven by the pressure, momentum, or reactive thrust of a moving fluid, such as water, steam or hot gasses.
Hydroelectric [hahy -droh -i -lek-trik] pertaining to the generation and distribution of electricity derived from the energy of falling water.
Transformer [trans-fawr -mer ] an electric device consisting of two or more windings wound on the same core, which changes the voltage of the electric energy.
Pylon [pahy -lon ] a steel tower carrying high-tension lines, telephone wires, or other cables and lines.
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