Can somebody tell me the advantages of using a rheostat and a potentiometer?
This is a vauge question, a rheostat is essentially a potentiometer, but the difference it that it's designed to handle much higher voltage and current. All that potentiometers are is a three-terminal resistor, for adding resistance. And a rheostat is just a larger form of a resistor.
Although I will agree that the question is vague, please don't misinform the OP. A potentiometer is a little more than just a 3 terminal resistor.
A 'pot' as they are called is a fixed resistor with 2 terminals normally found on resistors. The third terminal is the wiper which travels the whole length of the resistor. It's resistance to the end terminals varies as its position is changed. Obviously when the wiper is at one end its resistance is minimum to one terminal and maximum to the other. Alot of times a pot is simply used as a variable voltage divider. A rheostat is a pot with a much higher current rating but most of the time they are NOT used as a variable voltage divider. They usually are found wired in series with the load. A rather inefficient way of controlling load current. They are seldom used these days.
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