In summary, the conversation is about solving a circuit diagram to find the equivalent resistance between two points. The person attempted to solve the problem by eliminating wires without resistors and using the rules for resistors in series and parallel. However, they were unsure about which resistors were in series or parallel and asked for clarification and advice on numbering the resistors and simplifying the circuit. They also mentioned using the rule that resistors with the same voltage drop are in parallel. The expert advised them to follow the given advice and provided a summary of the conversation.
  • #1
Arka420
28
0

Homework Statement

: [/B]Given the circuit diagram, find the equivalent resistance between points P and Q.
ngodxd.png

Homework Equations

: [/B]ΔVloop = 0, ΔIjunction = 0 and V = IR

The Attempt at a Solution

: [/B]Eliminating the wires with no resistors and solving for resistance gives me the answer as (11/10) R, which is not the answer. I'm confused as to which resistors are in parallel and which resistors are in series.
 
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  • #2
Perhaps start by numbering the resistors A, B, C etc and post the drawing again.

Tell us which you think are in series or parallel. For example "I think A is in series/parallel with..."

Normally this type of problem is simplified by replacing two resistors in series or parallel with one and redrawing the circuit. You've posted the original so show us the first step/simplification that you made.
 
  • #3
Arka420 said:

Homework Statement

: Given the circuit diagram, find the equivalent resistance between points P and Q.
ngodxd.png
[/B]

Homework Equations

: ΔVloop = 0, ΔIjunction = 0 and V = IR[/B]

The Attempt at a Solution

: Eliminating the wires with no resistors and solving for resistance gives me the answer as (11/10) R, which is not the answer. I'm confused as to which resistors are in parallel and which resistors are in series. [/B]
Post your working out. We have no way of knowing where you went wrong (and therefore how to help you/ correct any mistakes) if we can't see your reasoning, but the attempt at the problem appears to be right (eliminate the short wire and simplify using the rules for resistors in series/ parallel).
 
  • #4
Remember also the rule that if multiple resistors have the same voltage drop associated with them then they are parallel
 
  • #5
This is how I worked out the circuit. Is it correct?
24ex442.png
 
  • #6
Arka420 said:
This is how I worked out the circuit. Is it correct?
24ex442.png
Not correct.

Follow this advice:
CWatters said:
Perhaps start by numbering the resistors A, B, C etc and post the drawing again.

Tell us which you think are in series or parallel. For example "I think A is in series/parallel with..."
 

What is equivalent resistance?

Equivalent resistance is the measure of a single resistor that would produce the same effect as multiple resistors connected in a circuit.

Why do we need to calculate equivalent resistance?

In a circuit, resistors are often connected in series or parallel. Calculating the equivalent resistance allows us to simplify the circuit and determine the overall resistance of the circuit.

How do you calculate equivalent resistance in a series circuit?

In a series circuit, the equivalent resistance is equal to the sum of all the individual resistances. It can be calculated by adding the values of all the resistors in the circuit.

How do you calculate equivalent resistance in a parallel circuit?

In a parallel circuit, the equivalent resistance is less than the smallest individual resistance. It can be calculated using the formula 1/Req = 1/R1 + 1/R2 + ... + 1/Rn, where Req is the equivalent resistance and R1, R2, etc. are the individual resistances.

What are the consequences of not calculating equivalent resistance correctly?

If equivalent resistance is not calculated correctly, it can lead to incorrect calculations of current and voltage in a circuit. This can result in unexpected performance or damage to the circuit components.

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