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HOW variable resistor is adjucted in circuit? why variable resistor has three terminals?
- zubair farooq (age 20)
The three-terminal variable resistor is also known as the potentiometer. Here is a nice diagram of the potentiometer:http://www.pictutorials.com/variable_resistor.gif
If only two terminals are used (the middle one and either A or B), the potentiometer acts as a usual variable resistor. Since the resistance of a linear resistive material is proportional to its length, turning the knob and changes the resistance.
The potentiometer serves as a voltage divider when all three terminals are used. The output voltage across the middle lead and either A or B can be adjusted while the voltage across A and B remains the same.
(published on 02/13/12)
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