What is the solution to the non-linear device problem?

  • Thread starter Thread starter jegues
  • Start date Start date
  • Tags Tags
    Device Non-linear
AI Thread Summary
The discussion centers on solving a non-linear device problem using Kirchhoff's voltage law (KVL). The user initially struggles with the equation involving voltage and current ratios, specifically \(\frac{1+v_Q/i_Q}{2+v_Q/i_Q} = 10\). They clarify that the 1-ohm resistor is in parallel with a 10V source, leading to a voltage drop calculation that includes the current through another resistor. After reevaluating their approach, they recognize the error in equating resistance to voltage and arrive at a solution of \(V_{q} = 2V\). The conversation emphasizes the importance of correctly applying KVL and understanding the relationships between voltage and resistance in circuit analysis.
jegues
Messages
1,085
Reaction score
3

Homework Statement


See figure


Homework Equations





The Attempt at a Solution



Again, see figure I tried something and it looked promising but the answer doesn't work out.

Any ideas?
 

Attachments

  • NLDQ.jpg
    NLDQ.jpg
    18.7 KB · Views: 486
Physics news on Phys.org
Could you explain your reasoning to get the equation

\frac{1+v_Q/i_Q}{2+v_Q/i_Q} = 10

I don't see how you're applying Kirchoff's voltage law to get that.
 
You know the 1 ohm resistor is in parallel with the 10V source, therefore the voltage across it is 10V. Now we can subtract from the 10V the drop across the other 1 ohm resistor which is 1*Iq, and subtract Vq. 10 - 1*Iq - Vq=0, we can plug in for Iq which is Vq^2+2*Vq. Solve for Vq, you'll obtain a positive and negative value but only the positive makes sense because of our polarity.
 

Attachments

  • circuit.jpg
    circuit.jpg
    4.9 KB · Views: 418
When you combine the circuit resistances, first by adding the two in series, and then by calculating the two in parallel, you get a value of resistance (keep in mind SI units).

In your equations you say this resistance is equal to 10 volts by KVL.

\frac{1+v_Q/i_Q}{2+v_Q/i_Q} = 10

Resistance does not equal voltage.
 
Thanks for the responses. I must have been out of it at the time putting resistance equal to voltage lol.

I understand now.

V_{q} = 2V
 
Thread 'Have I solved this structural engineering equation correctly?'
Hi all, I have a structural engineering book from 1979. I am trying to follow it as best as I can. I have come to a formula that calculates the rotations in radians at the rigid joint that requires an iterative procedure. This equation comes in the form of: $$ x_i = \frac {Q_ih_i + Q_{i+1}h_{i+1}}{4K} + \frac {C}{K}x_{i-1} + \frac {C}{K}x_{i+1} $$ Where: ## Q ## is the horizontal storey shear ## h ## is the storey height ## K = (6G_i + C_i + C_{i+1}) ## ## G = \frac {I_g}{h} ## ## C...

Similar threads

Replies
3
Views
2K
Replies
8
Views
2K
Replies
3
Views
2K
Replies
9
Views
2K
Replies
16
Views
3K
Replies
6
Views
2K
Back
Top