- #1
vadevalor
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Why is the potential at X , denoted by V, not
V/8 = 4.8/(4.8+7.6) ? Why is numerator of resistance part 7.6 and not 4.8 by potential divider principle?
Answer is A but i dont understand the solution as there are 'conflicting battery direction' and i dont know how to start
hi vadevalor!
start by replacing the three batteries by one 3V battery …
what is the potential at Y? and where is that measured from?
and now adjust that to start from X instead
Should i put the 3v battery to the right or left of X and should i go from + terminal to -terminal from X to Y like current flow or electron flow?
Smiles :D
hi vadevalor!
you must always always ALWAYS use current flow not electron flow!
X is somewhere in the middle of the 3V battery, isn't it?
Above for potential divider i was told to look at electron flow
hi vadevalor!
conventionally, the current flows from the positive terminal (long line) to the negative terminal (short line)
(the electrons, of course go the other way, towards the positive!)
so the short line is at zero potential, and you have to start from the short line to get to X to find the potential at X, ie the potential difference from zero
(see eg "Electric Potential Diagrams" at http://www.physicsclassroom.com/class/circuits/u9l1c.cfm)
ie you go through the 7.6Ω, so 7.6 is in the numerator
Its the third paragraph from your first answer :) starting from the short line (electron flow direction)