Equivalent Resistance between A and D

In summary, the conversation discusses how to calculate the effective resistance of a circuit and the overall capacitance if the resistors were replaced with capacitors. The suggested method is to simplify the circuit by redrawing it and identifying resistors in parallel or series. The rules for adding resistors or capacitors in parallel and series are also mentioned.
  • #1
FamishedPluto7
2
0

Homework Statement


I came across a problem and I was unable to understand how the effective resisitance of this circuit is to be calculated.
(Please refer to image uploaded)

Homework Equations

The Attempt at a Solution


Well I assumed that current tends to flow through wires without resistances preferably.
So I traces out a path such that the current flows from A to C without going theough B, then divides into 2 pathways, one containing 3ohm. The other, 1ohm.
Can somebody guide me with the correct equivalent resistance between A and D
Plus, let's say there were capacitors instead of the resistors, the values of their capacitances being same in magnitude as the resisitances in the image below. What would be the overall capacitance then?
 

Attachments

  • image.jpg
    image.jpg
    50.7 KB · Views: 485
Physics news on Phys.org
  • #2
What you could try doing is simplifying the circuit.
Draw a diagram in which the points are placed separate enough, and draw the resistances in between.

Now pass current from A to C. You'll see that there will have to be current in more than just one path from A to D.

Hope this helps.
 
  • #3
Qwertywerty said:
What you could try doing is simplifying the circuit.
Draw a diagram in which the points are placed separate enough, and draw the resistances in between.

Now pass current from A to C. You'll see that there will have to be current in more than just one path from A to D.

Hope this helps.
Thank you for your response, but I really have no clue as to how I can simplify this diagram more than this, if only I could do that, this would be easier to solve
 
  • #4
FamishedPluto7 said:
Thank you for your response, but I really have no clue as to how I can simplify this diagram more than this, if only I could do that, this would be easier to solve
Mark points A, B, C and D, at the corners of say, a square. Now join the points appropriately using the wires/resistances.
 
  • #5
FamishedPluto7 said:
Thank you for your response, but I really have no clue as to how I can simplify this diagram more than this, if only I could do that, this would be easier to solve
It's a bit like a game of snakes and ladders. Imagine that A has some positive voltage and you are a positive charge and you have to move from A to D while always dropping down in voltage. Use a different colour pencil and trace out all the alternative paths you can find that take you from A to D while descending the voltage gradient. Every alternative path here represents a resistance in parallel.

You'll recognize, too, that point B is really just point D with another name, and point C is electrically identical to A.
 
  • #6
you can redraw this circuit to make it VERY simple.
hint: what is the definition of resistors in parallel and resistors is series.
 
  • #7
FamishedPluto7 said:
Plus, let's say there were capacitors instead of the resistors, the values of their capacitances being same in magnitude as the resisitances in the image below. What would be the overall capacitance then?

The rules for
adding resistors in series : Rtotal = R1 + R2 + R3 + ...
adding resistors in parallel : Rtotal = 1 ÷ (1/R1 + 1/R2 + 1/R3 + ...)

so

how does this differ for
adding capacitors in parallel?
adding capacitors in series?
 

1. What is the definition of Equivalent Resistance between A and D?

The equivalent resistance between A and D is the single resistance value that can replace a complex network of resistors between the two points and produce the same total resistance.

2. How is Equivalent Resistance between A and D calculated?

The equivalent resistance is calculated using the formula Req = R1 + R2 + R3 + ..., where R1, R2, R3, etc. are the individual resistances in the network between points A and D. If the resistors are in parallel, the formula becomes Req = 1/(1/R1 + 1/R2 + 1/R3 + ...).

3. What is the significance of Equivalent Resistance between A and D?

The equivalent resistance is important because it simplifies complex networks and allows us to analyze and understand their behavior more easily. It also helps in designing circuits and choosing appropriate resistors for a desired resistance.

4. How does the number of resistors in the network affect the Equivalent Resistance between A and D?

The equivalent resistance will decrease as the number of resistors in the network increases. This is because resistors in parallel provide an easier path for current to flow, reducing the overall resistance. However, if the resistors are in series, the equivalent resistance will increase with the addition of more resistors.

5. What happens to the Equivalent Resistance between A and D if one resistor in the network is changed?

The equivalent resistance will change if the value of one resistor in the network is changed. It may increase or decrease depending on the position of the resistor and its value relative to the other resistors in the network. This is why it is important to calculate the equivalent resistance when designing circuits to ensure the desired resistance is achieved.

Similar threads

  • Introductory Physics Homework Help
Replies
5
Views
1K
  • Introductory Physics Homework Help
Replies
4
Views
1K
  • Introductory Physics Homework Help
Replies
15
Views
1K
Replies
10
Views
2K
  • Introductory Physics Homework Help
Replies
2
Views
1K
  • Introductory Physics Homework Help
Replies
4
Views
3K
  • Introductory Physics Homework Help
Replies
8
Views
1K
  • Introductory Physics Homework Help
Replies
4
Views
2K
  • Introductory Physics Homework Help
Replies
4
Views
942
  • Engineering and Comp Sci Homework Help
Replies
5
Views
3K
Back
Top