What is the Differential Equation for the Current in an Auto Induction Circuit?

  • Thread starter Thread starter toetoe
  • Start date Start date
  • Tags Tags
    Auto Induction
AI Thread Summary
The discussion revolves around finding the differential equation for current in an auto induction circuit after a switch is opened. The user has proposed the equation (R+r)*i + L(di/dt) = 0 but is uncertain whether to include the total resistance (R+r) or just the resistance r in the equation. There is a request for clarification on the correct formulation of the differential equation. The user expresses frustration over the lack of responses to their query. The thread highlights the challenges faced in understanding circuit dynamics and the need for expert guidance.
toetoe
Messages
4
Reaction score
0

Homework Statement


i tried to put all data in the image .

http://img136.imageshack.us/img136/7443/photokg6.th.jpg

in the initial situation K was closed.in T = 0 ,K was opened.

give the differenciel equation of the courant.

The Attempt at a Solution



(R+r)*i + L (di)/(dt) = 0 .

my problem is that i don't know if we have to put (R+r)*i or only r*i in the differentiel equation of the courant .

thanks in advance for any help.
 
Last edited by a moderator:
Physics news on Phys.org
by the way,if there is something not clear in the data of the problem ,i will be happy to explain it.
 
does nobody know the solution?
 
no answer !:(
 

Thread 'Errors and significant figures'

I multiplied the values first without the error limit. Got 19.38. rounded it off to 2 significant figures since the given data has 2 significant figures. So = 19. For error I used the above formula. It comes out about 1.48. Now my question is. Should I write the answer as 19±1.5 (rounding 1.48 to 2 significant figures) OR should I write it as 19±1. So in short, should the error have same number of significant figures as the mean value or should it have the same number of decimal places as...
View full post »
Thread 'A cylinder connected to a hanging mass'

Thread 'A cylinder connected to a hanging mass'

Let's declare that for the cylinder, mass = M = 10 kg Radius = R = 4 m For the wall and the floor, Friction coeff = ##\mu## = 0.5 For the hanging mass, mass = m = 11 kg First, we divide the force according to their respective plane (x and y thing, correct me if I'm wrong) and according to which, cylinder or the hanging mass, they're working on. Force on the hanging mass $$mg - T = ma$$ Force(Cylinder) on y $$N_f + f_w - Mg = 0$$ Force(Cylinder) on x $$T + f_f - N_w = Ma$$ There's also...
View full post »

Similar threads

Understanding self-inductance in a solenoid.
Replies
3
Views
1K
Voltage and current as functions of time for a series RL circuit
Replies
18
Views
3K
Calculation of current in driven series RLC circuit
Replies
8
Views
2K
Solving Equation to Analyze Steady State Current
Replies
7
Views
2K
Determining Inductance L in an LC Circuit
Replies
5
Views
2K
Understanding a very simply RL circuit
Replies
1
Views
745
Deriving ODEs for straight lines in polar coordinates for a given Lagrangian
Replies
8
Views
1K
Self-inductance of LC circuit given rate of capacitor discharge.
Replies
6
Views
866
What happens to a coil of wire as current is increased?
Replies
4
Views
2K
Does Mutual Inductance Affect Voltage in an Open Circuit?
Replies
1
Views
1K

Hot Threads

Recent Insights

Back
Top