Calculate the total resistance

In summary, the conversation is about a user asking for their answer to be checked for a circuit problem involving resistance. The conversation includes a discussion about the correct approach to solving the problem and the correct answer being provided.
  • #1
Fatima Hasan
319
14

Homework Statement



viber-image.jpg


Homework Equations


[/B]
R_b%3D%5Cfrac%7BR_a*R_b%7D%7BR_a+R_b%7D.gif


The Attempt at a Solution



2.jpg

%20%5Cfrac%7B200%7D%7B9%7D%20+%206%20%3D%206.gif
[/B]
Could anyone check my answer please ?
 

Attachments

  • viber-image.jpg
    viber-image.jpg
    17.7 KB · Views: 1,333
  • R_b%3D%5Cfrac%7BR_a*R_b%7D%7BR_a+R_b%7D.gif
    R_b%3D%5Cfrac%7BR_a*R_b%7D%7BR_a+R_b%7D.gif
    835 bytes · Views: 720
  • 2.jpg
    2.jpg
    16.7 KB · Views: 870
  • %20%5Cfrac%7B200%7D%7B9%7D%20+%206%20%3D%206.gif
    %20%5Cfrac%7B200%7D%7B9%7D%20+%206%20%3D%206.gif
    5.3 KB · Views: 968
Physics news on Phys.org
  • #2
What is RT? What is the total resistance?

Usually an answer is easier to check than to get - calculate voltages and currents and see if they work out.
 
  • #3
Why are you taking ##R_1## and ##R_2## to be in parallel? Here's what your circuit looks like after your ∇ to Y transformation:

upload_2018-10-26_9-55-37.png
 

Attachments

  • upload_2018-10-26_9-55-37.png
    upload_2018-10-26_9-55-37.png
    1.4 KB · Views: 835
  • #4
Just to be clear, your 6.22 Ohm answer is clearly wrong for the reason outlines by gneill.
 
  • #5
gneill said:
Why are you taking ##R_1## and ##R_2## to be in parallel? Here's what your circuit looks like after your ∇ to Y transformation:

View attachment 232843
26%7D%5C%5C%5C%5C%3D6+%5Cfrac%7B15%7D%7B26%7D+%5Cfrac%7B609%7D%7B26%7D%3D30%20%5COmega.gif
 

Attachments

  • 26%7D%5C%5C%5C%5C%3D6+%5Cfrac%7B15%7D%7B26%7D+%5Cfrac%7B609%7D%7B26%7D%3D30%20%5COmega.gif
    26%7D%5C%5C%5C%5C%3D6+%5Cfrac%7B15%7D%7B26%7D+%5Cfrac%7B609%7D%7B26%7D%3D30%20%5COmega.gif
    3.5 KB · Views: 504
  • #6
Much better!
 
  • Like
Likes Fatima Hasan

1. What is total resistance and why is it important to calculate?

Total resistance is the overall opposition to the flow of electric current in a circuit. It is important to calculate because it helps us determine the amount of current that will flow through a circuit and how much power will be consumed by the circuit components.

2. How do you calculate total resistance in a series circuit?

In a series circuit, total resistance is the sum of individual resistances. This means that you add up all the resistances in the circuit to get the total. Mathematically, it can be represented as: Rtotal = R1 + R2 + R3 + ... + Rn

3. How do you calculate total resistance in a parallel circuit?

In a parallel circuit, total resistance is calculated differently. The reciprocal of total resistance is equal to the sum of the reciprocals of individual resistances. This can be represented as: 1/Rtotal = 1/R1 + 1/R2 + 1/R3 + ... + 1/Rn

4. What is the unit of measurement for total resistance?

Total resistance is measured in ohms (Ω), which is the SI unit for electrical resistance. It is named after German physicist Georg Ohm, who first discovered the relationship between voltage, current, and resistance in an electrical circuit.

5. Can total resistance ever be negative?

No, total resistance can never be negative. Resistance is a physical property of a material and it cannot be negative. However, in some cases, the calculated value of total resistance may appear negative due to incorrect calculations or using the wrong formula. In such cases, it is important to double check the calculations and formulas used.

Similar threads

Engineering Finding the Armature Resistance from winding/coil resistance
    • Engineering and Comp Sci Homework Help
Replies
1
Views
1K
Calculating Copper Wire Gauge for Resistance Thermometer Bridge Circuit
    • Engineering and Comp Sci Homework Help
Replies
6
Views
1K
How to find the equivalent resistance of this electric circuit?
    • Engineering and Comp Sci Homework Help
Replies
5
Views
3K
Find the Norton equivalent resistance
    • Engineering and Comp Sci Homework Help
Replies
2
Views
2K
Equivalent resistance with a capacitor
    • Engineering and Comp Sci Homework Help
Replies
11
Views
5K
Calculating Total Resistance in a Parallel Circuit
    • Engineering and Comp Sci Homework Help
Replies
2
Views
1K
Engineering Part C: Solving Resistance in a Complex Circuit
    • Engineering and Comp Sci Homework Help
Replies
12
Views
2K
Engineering Calculate the resistance in the circuit
    • Engineering and Comp Sci Homework Help
Replies
5
Views
1K
Can't find total resistance in a complex star circuit
    • Engineering and Comp Sci Homework Help
Replies
20
Views
1K
Why is the Thevenin resistance in this problem 3.2 kΩ?
    • Engineering and Comp Sci Homework Help
Replies
17
Views
2K

Hot Threads

Recent Insights

Back
Top