Voltage Read with op-amp

[JohnLincoln]

@vj01

however im having a issue with wires. for example i use a short wire and the readings are 12.8 at 12v from my bench power supply however when i use a long wire more then a meter i get 12.1 which is a lot more closer to the value i require. i know its due to resistance in the wire and a fixed resistor would help, however where would i put it.

The resistance of any wire that you use should be negligible in comparison to the 10kΩ and 100kΩ resistors.