How to determine the position of the slider on a potentiometer

[lew123189]

Homework Statement

This circuit shows a 10Kohm potentiomiter with a 5Kohm load.

determine the position of the slider on the 'pot' when the voltage acreoss points 'xx' is 3V


ok so the 10K resistor is a potentiometer which is a variable resistor, so what they are asking when they say the position of the slider is what value is the 10Kohm resistor actually set to, is that right??

I understand that I need to split the 10Kohm resistor into 2 like i have done on FIG2

I also know that both resistors make 10K ohms.

I am assuming that is the slider was in the middle each resistor would have 5KOHM, therefore is it was a quarter of the way up one resistor would be 2.5K and the other would be 7.5KOHM


So what I need to find is the value of R1 and R2.

So what formula do I need to use for this?



Thanks a lot,

Lewis

 

[NascentOxygen]

Hi. Position of the slider can be expressed as a fraction (or a percentage) of the total track resistance, i.e., express R2 as a percentage of the total R1 + R2.

You don't need a formula; you apply Kirchoff's Laws. Note that the current through R1 splits and some goes through R2 and the rest through the load.