Where did I go wrong while solving for R_L?

  • Thread starter PainterGuy
  • Start date
In summary: So the last term in the equation should be -45V, not -9V.In summary, the conversation is about finding the maximum power value for a given R_L and the use of nodal analysis and Norton's theorem to solve the problem. The individual seeking help made an error in their loop 1 equation, which was pointed out by gneill. They also encountered a discrepancy in their answer when using I_sc, which was due to overlooking a multiplication step in their equation.
  • #1
PainterGuy
940
70
Hi, :smile:

I was finding the value R_L for which maximum power takes place. Maximum power takes place when R_L = R_Th. Please have a look on the following link; you can see my answer is different: http://img215.imageshack.us/img215/7743/imgtb.jpg

Where did I go wrong?:confused: Please help me out. Many thanks.
 
Physics news on Phys.org
  • #2
Your loop 1 equation looks to be incorrect. I see -9I1 rather than -7I1.
 
  • #3
Thanks a lot, gneill. You are correct. I have made an error.

Regards,
 
  • #4
Hi again, gneill

Please help me!

1: I have also used nodal analysis to solve the problem. Please have a look here: http://img838.imageshack.us/img838/1970/prob1x.jpg

What is your answer to "Ref 1"? Is my answer correct?

2: I have tried nortonized the circuit and tried to find I_N using I_sc. Please have a look here: http://img39.imageshack.us/img39/3187/prob2s.jpg

My answer is not correct as you can see. The V_Th and R_th found previously in previous posts produce different value for I_N than the one found using I_sc. What did go wrong?

Please help me out. Many, many thanks.

Regards
 
  • #5
PainterGuy said:
Hi again, gneill

Please help me!

1: I have also used nodal analysis to solve the problem. Please have a look here: http://img838.imageshack.us/img838/1970/prob1x.jpg

What is your answer to "Ref 1"? Is my answer correct?
Looks good.
2: I have tried nortonized the circuit and tried to find I_N using I_sc. Please have a look here: http://img39.imageshack.us/img39/3187/prob2s.jpg

My answer is not correct as you can see. The V_Th and R_th found previously in previous posts produce different value for I_N than the one found using I_sc. What did go wrong?

After you substituted for I2 in the loop 1 equation, you went on to clear the 5 in the denominator by multiplying through by 5. Unfortunately, you overlooked multiplying the 9V on the RHS of the equation by 5 also.
 

FAQ: Where did I go wrong while solving for R_L?

Why is my calculated value for R_L different from the expected value?

There could be several reasons for this discrepancy. It could be due to measurement error, incorrect assumptions made during the calculation, or a mistake in the calculation itself. Double-check your work and make sure all values are accurate.

Why does my calculated value for R_L result in a negative resistance?

This could occur if the direction of current flow is not correctly accounted for in the calculation. Check your circuit diagram and make sure all values and directions are correct. It could also be due to an incorrect application of Ohm's Law.

Is it possible to have multiple values for R_L that satisfy the equation?

Yes, it is possible to have multiple solutions for R_L. This could occur if there are multiple unknown variables in the equation or if the equation is not linear. In this case, additional information or equations may be needed to determine the exact value for R_L.

Why is my calculated value for R_L different from the expected value, even though I used the correct formula?

This could be due to using the incorrect units for the given values. Make sure all units are consistent and convert if necessary. It could also be due to rounding errors, so try using more precise values in your calculations.

Can I use the same formula for calculating R_L for all types of circuits?

No, different types of circuits may require different formulas or approaches to calculate the resistance. Make sure you are using the correct formula for the specific circuit you are working with. Additionally, the formula may need to be modified for more complex circuits.

Similar threads

Find the resistance for maximum power transfer
Replies
7
Views
3K
Understanding maximum power transfer theorem
Replies
5
Views
5K
Block and wedge problem -- Where am I going wrong?
Replies
7
Views
559
Where Did I Go Wrong in My Refraction Problem Solution?
Replies
11
Views
928
Where did I go Wrong? Solving for Particle Speed with Mass & Charge
Replies
13
Views
2K
Where Did I Go Wrong in Calculating Net Current Through a Circle?
Replies
6
Views
2K
Max power of a photovoltaic cell -- where did I go wrong?
Replies
4
Views
1K
Measurements Calculation Problem
Replies
3
Views
546
Calculating Uncertainty: Where Am I Going Wrong?
Replies
3
Views
1K
Ruler measurements and knowing how many decimal places to include
Replies
9
Views
746

Hot Threads

Recent Insights

Back
Top