Three voltmeters are connected in parallel across the output of a voltage source:

#1 reads 12.23 v

#2 reads 12.1 v

#3 reads 12.2 v

what is the probable voltage indicated by this set of readings?

12.18 Volts.

Explanation:

Since these voltmeters are connected in parallel.So the voltage across the parallel connection remains the same but all the three voltmeters are giving different reading this may be because of the different resistances in the wires connected to the voltmeters.

So the probable voltage is the mean of the readings.

probable voltage=

=12.18 Volts.