Beginners question

[cob]

Hi,
This looks like a great forum. I am just getting started and have a very basic question. I understand that the flow in a circuit goes from + to - but in looking at the following basic schematic I'm wondering why there is no current flow (per the arrows in the schematic) from points 2 to 7 and 3 to 6. Given the rule that the current will follow the path of least resistance I suppose that because resistors 1 and 2 sit on the path from points 2 to 7 and 3 to 6 respectively then the current doesn't flow down those paths. Am I correct in assuming that? So, for example, without resistor 1 the flow could go from point 8 to 7 to 6 to 3 to 2 then to 1 or 7 again. But if this is the case why does the schematic show current from 8 to 7 to 2 to 1 i.e. up through resistor 1? Thanks in advance.

**broken link removed**

 

[colin55]

The circuit you have drawn is purely a resistive circuit and you have shown arrows according to electron flow. Electrons flow from negative to positive and conventional current flows from positive to negative. Normally a simple circuit such as this is expressed as conventional current flow and the arrows are reverse to the direction shown above.
You must say "I understand that conventional current flow is positive to negative or electron flow is from negative to positive."
The diagram does show electron flow from 7 to 2 and 6 to 3.

 

[cob]

Hmmm. Thanks for the response but my question is, in this circuit, why doesn't the diagram show flow from, for example, 7 to 6 to 3 to 2 and then back to 7 again? Why does all the flow in this diagram at point 2 go to pt. 1 and not to pt. 7? I know I'm missing some basic theory or the diagram is wrong but I don't know which. And. btw, your point about the conventional flow direction is well taken.

 

[colin55]

I don't know what you mean.

 

[cob]

Why is there no current flow from point 2 to point 7 or from point 3 to point 6? Also, why is there none from point 2 to point 3 or from point 3 to point 4?

 

[colin55]

I don't know what you mean.

 

[cob]

I don't know what you mean.

Ah ok-don't worry about it. Someone else will respond. It's not too difficult a question.

 

[colors]

read kirchoff's law.

 

[JimB]

Referring to my modified version of your diagram shown attached.

I have used conventional current notation rather than electron flow as used in the original diagram.

The source of voltage is connected to three resistors R1, R2 and R3.
The voltage across each resistor is the same, the connections are very low resistance, we can neglect this resistance.

A current flows through each resistor, I1 flows through R1, I2 through R2, and I3 through R3.

Using ohms law, I1 = V/R1, I2 = V/R2 and I3 = V/R3.

I4 = I2 + R3, I5 = I4 + I1 and I5 = I1 + I2 + I3

There are three individual currents I1 I2 and I3 in the three resistors, each of these currents flows from the battery (voltage source), through the associated resistor and back to the battery.

In the connections between the resistors:

Between R2 and R3, the current is simply I3.

Between R1 and R2, the current is I4 = I2 + I3

Between the battery and R1, the current is I5 = I1 + I4 = I1 + I2 + I3

I hope this description helps.

JimB

 

[Gary B]

Given the rule that the current will follow the path of least resistance**broken link removed**

Wrong, there is no such rule! The current divides proportionally to the inverse of the resistance of each branch. If you believe in Ohm’s law “I=E/R” then you cannot believe in you statement that the current follows the lowest resistance path. Also, engineers use conventional current flow because it makes the arithmetic come out right, technicians use electron flow because that is the way the universe actually works. Technicians mostly hang out in this forum so be ready to reverse your thinking depending upon who answers a question.

While I agree that you should go over Kirchhoff’s law, the important thing in this case that current can only go in one direction in any device. If it is flowing up in R1, it cannot also be flowing down in R1 at the same time which is what you imply asking about 7 6 3 2 7 path given the 1 8 7 2 1 and 1 8 7 6 3 2 1 paths.

 

[cob]

Ok-thanks for the information.

 

[Bilal]

hi'
this is not d thing u may b thinking about but
this is Electronics .So v should c, read and understand ,wt d electronics say?

look at the resistors ( R1 And R2 ) potential at their ends
c

1. Point7 is -ve with respect to (w.r.t) point2.
Result: According to "Electronic Current flow rule" current should flow from 7-to-2.

2. Point6 is also -ve w.r.t point3.
Result: According to "Electronic Current flow rule" current should flow from 6-to-3.

This is not the marathone race that a person must come to d starting point?????
In Electronics , c the potential difference at c legs of componenets for analysis.
In Electronics , u should 1st decide wt type of current flow rule u would like to adopt b4 analysis.
ELECTRONIC ( -ve to +ve ) OR CONVENTIONAL ( +ve to -ve )!
Understood?
I don't know u understood or not?????????????????????????????????????????????

u can contact. waiting.......!
my e- mail is jawaidk0@gmail.com

 

[Bilal]

current flow

hi,
hru
i read ur post
i tried to explain u against ur qurey
u understood???????????

 

[Bilal]

C d ELECTRONICS RULES ( BASICS )

HI,
hru?

In Electronics u should c , read, and folow the rules b4 d circuit analysis.
In Electronics u 1st decide which current flow rule ,u would like to adopt?
ELECTRONIC ( -ve to +ve ) OR CONVENTIONAL ( +ve to -ve ).

c the circuit ( Electronic flow )

C d potential difference at the points of R! & R2.

R1: Potential of point7 is -ve with respect to ( w.r.t ) point2.
Result: Current should flow from 7 to 2.
R2: Potential of point6 is -ve with respect to ( w.r.t ) point3.
Result: Current should flow from 6 to 3.

this is ELECTRONICS not d marathone etc race game.

UNDERSTOOOOOOOOOOOOOOOOOOOD?

I tried but
I don't know i could properly reply/explain or not?

ok take care .
Buy