# Laplace transform

1. Oct 7, 2014

### ranju

1. The problem statement, all variables and given/known data
we have to solve the given circuit using laplace transform for i(t) for t>0 when switch k opened at t=0..
now all I wnated to make clear is the final circuit diagram of this in s-domain..

2. Relevant equations

3. The attempt at a solution
as I solved I considered the circuit to be in steady state before switch is opened so , current across inductor is 6A...

#### Attached Files:

File size:
53.5 KB
Views:
78
• ###### IMG_20141007_181609.jpg
File size:
48.1 KB
Views:
76
2. Oct 7, 2014

Images are not clear.

3. Oct 7, 2014

What is i(0+) you are getting ?

4. Oct 7, 2014

### ranju

well only the left hand portion is'nt clear.. in 1st pic.. there is 12V voltage source & in 2nd pic it is 12/s in s-domain..
i(0+)=i(0-) = 6A..

5. Oct 7, 2014

can you show your working for i(0-).

6. Oct 7, 2014

### ranju

sorry actually I did a calculation mistake..i(0-) =4 A.. and I found the equivalent current of the circuit considering it in steady state before switch is opened.. so the inductor is dhorted so the whole 4 A current pass across the inductor branch..!!

7. Oct 7, 2014

Are you sure the current will be 4 A,mine is coming 14 A.

8. Oct 7, 2014

### ranju

you are right .. ..

9. Oct 7, 2014

10. Oct 7, 2014

### ranju

thanks and additional thanks for correcting that mistake.. :p

11. Oct 7, 2014