# dumb beginner question

Discussion in 'General Electronics Chat' started by grumm, Apr 28, 2012.

1. ### grumm Thread Starter Member

Apr 28, 2011
10
0
Hello, I've stuck up some questions and pictures of the extremely basic
voltage divider circuit I'm trying to understand at:
http://members.upc.ie/marilyn.mcconnell/voltageDiv.html
so far I've looked at several chapters of the tutorials here. I thought
I'd try to build some simple circuits, but maybe I'm not ready yet. Anyway,
I'm hoping someone can explain this voltage divider to me.
Thanks for any help,
Gerard

2. ### MrChips Moderator

Oct 2, 2009
18,374
5,804
Current tends to flow through the path of least resistance.

With the 1kΩ + 1kΩ voltage divider, current prefers this path that the path with the 10kΩ resistor.
Hence the voltage divider equation can be applied.

With the 100kΩ + 100kΩ voltage divider, current is diverted to the 10kΩ resistor and the voltage divider equation is no longer valid.

The voltage divider represents a current source. The 10kΩ resistor is a current load.

A basic rule of thumb is make sure the resistance of the load is greater than ten times that of the source.

Feb 17, 2009
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4. ### strantor AAC Fanatic!

Oct 3, 2010
4,993
3,079
R3 is in parallel with R2. R2 & 3 are in series with R1.
combine the parallel resistance of R2 & R3, you get 9090Ω
now, do your voltage divider equation.
now take the result of your voltage divider equation to figure the current through R3 & the meter.

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5. ### J0ker New Member

Apr 18, 2012
17
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Current tends to flow...more through the path of least resistance we should say, shouldn't we? Because some current flows to other paths too.

6. ### iONic AAC Fanatic!

Nov 16, 2007
1,640
94
In theory the 10K resistor is inhibiting your understanding of a voltage divider as it is altering the "ideal" voltage divider concept. Remove the 10K resistor (R3) and as long as the values of R1 and R2 are equal, the voltage will always be halved.....until you apply the
multimeter to make the measurement (The meter has it's own internal resistance).

ALSO: "Dumb" beginner questions are the most intelligent of questions. The only dumb question is the one you already know the answer to, and even then, this is subject to opinion, and a second one is never a bad thing.

7. ### Wendy Moderator

Mar 24, 2008
21,604
2,978
These are core understandings that you build on, which is why we don't have a problem with questions for beginners. You get them down, then move on to the next concept.

8. ### grumm Thread Starter Member

Apr 28, 2011
10
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Brilliant, Many Thanks for the excellent explanations and encouragement.
I get it