• Support PF! Buy your school textbooks, materials and every day products Here!

Determine the total current in the attached diagram

  • Thread starter DevonZA
  • Start date
  • #1
181
6
Hope this is posted in the right place:

Determine the total current in the attached diagram

R parallel = 1/9.7 + 1/43 = 0.366^-1 = 2.98ohms
R series = 4.3 + 7.4 = 11.7ohms
R total = 2.98+11.7=14.68ohms

I=V/R
= 30/14.68
= 2.04A

The answer given is 4.67A, what am I doing wrong?

Thanks,
Devon
 

Attachments

Answers and Replies

  • #2
34,370
10,442
R series = 4.3 + 7.4 = 11.7ohms
Where does 7.4 come from and what is in series here?

If you use a number not given in the problem statement, please explain where it comes from.

There are more things in parallel.
 
  • #3
181
6
My apologies the 7.4 ohms should be where the second 4.3ohms in series is on the attached sketch. I drew that up late last night.
 
  • #4
CWatters
Science Advisor
Homework Helper
Gold Member
10,529
2,295
Hint: There are actually three resistors in parallel.
 
  • Like
Likes DevonZA
  • #5
181
6
Hint: There are actually three resistors in parallel.
I see only 2?
 
  • #6
181
6
Aha thank you CWatters I see that the 7.4ohm resistor is in fact in parallel.

Itotal=Vtotal/Rtotal
Rparallel = 1/9.7 + 1/4.3 + 1/7.4 = 2.12ohms
Rseries = 4.3ohms
Rt = 2.12 + 4.3 = 6.42ohms

It=Vt/Rt
It = 30/6.42
It = 4.67A
 
  • #7
CWatters
Science Advisor
Homework Helper
Gold Member
10,529
2,295
Looks right to me.
 
  • Like
Likes DevonZA

Related Threads on Determine the total current in the attached diagram

Replies
27
Views
1K
Replies
1
Views
17K
  • Last Post
Replies
9
Views
16K
Replies
4
Views
4K
  • Last Post
Replies
1
Views
3K
Replies
3
Views
1K
  • Last Post
Replies
13
Views
2K
Replies
5
Views
2K
Replies
3
Views
1K
Replies
1
Views
862
Top