IIT JEE , AIEEE Forum - Physics , Electricity - WHAT IS A POTENTIAL-DIVIDER?

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A voltage divider consists of two resistances R1 and R2 connected in series across a supply voltage Vs. The supply voltage is divided up between the two resistances to give an output voltage Vo which is the voltage across R2. This depends on the size of R2 relative to R1 :

Vo = Vs x R2 / (R1 + R2)

If R2 is much smaller than R1, Vo is small (almost 0) because most of the voltage is across R1.

If R2 is about the same as R1, Vo is about half Vs because the voltage is shared about equally between R1 and R2.

If R2 is much larger than R1, Vo is large (almost equal to Vs) because most of the voltage is across R2.

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