# Zero adjust resistance help please?

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hello there i kinda need help with this, image attached in the thread
this is the ohmmmeter circuit and i have two questions :
-what is the effect of R2 when it become lower than Rm?
-what is the effect of R2 when it become higher than Rm?

Rm=internal resistance of ohm-meter
R2=zero adjust resistance

edit:i study computer engineering techniques and this is the instrument and measurements
so hopefully this is the right place to post

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## Answers and Replies

gneill
Mentor
In your figure the bottom end of R2 is connected to the node where E and Rm connect, but the "wire" looks more sketchy than the other wires of the drawing. Is that connection intentional?

You need to make an attempt at a solution before we can offer any detailed help. Here's a hint though: You've identified R2 as a zero adjust resistance. What's the standard procedure for zero-adjusting an ohmmeter? Think about comparing the magnitudes of the currents passing through the meter Rm and R2.