Investigate power circuits for different types of household appliances and explain why different circuits are required for light and power.
Can u give me links to websites that may answer my question.
I don't really like this question, what do they mean by "power"?
Different power circuits are needed in different types of household appliances because each circuit is designed to manipulate current in such a way that it can achieve a certain purpose.
Example: a transistor needed an npn or a pnp junction for it to function in a way that achieves its purpose by acting like a switch while a light bulb will need a filament that heats up as current passes for light to be emitted.
It is not possible to use an npn junction to emit light under practical condition and nor is it possible for the filament in a light bulb is act as a transistor.
Therefore, different circuits are required depending on the purpose of its application.