# Find the current

1. Jul 3, 2017

### giokrutoi

1. The problem statement, all variables and given/known data
the image of circuit is in attachment
the question is to find the current through the battery

2. Relevant equations

3. The attempt at a solution
I think that there is a y connection
so above two and centered one form y from formula the whole resistance is 1
than I imagine bottomed ones and this and above ones as new y type connection and
I get 1/R = 1/(1/1 + 1/2 + 1/3) and r is equal to 11
all in all the current should be I=U/R = 3/11
but in book the answer is 21/19

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2. Jul 3, 2017

### vishnu 73

you can use delta to y conversion

3. Jul 3, 2017

### Staff: Mentor

Please show the formula used and the details of how you applied it for your Y to Δ transformation. What do you mean by the "whole resistance is 1"?

4. Jul 3, 2017

### vishnu 73

this is the your current equivalent circuit you could change it to the form of

using
sorry for my poor drawing skills

5. Jul 3, 2017

### giokrutoi

1/R = 1/(1/r1+1/r2+ 1/r3)

6. Jul 3, 2017

7. Jul 3, 2017

### vishnu 73

i am sorry i will draw again

the 3 and 2 are the same old resistors but Ra , Rb , Rc are resistances to be determined using the delta to y conversion hope this clears up
what i am saying is that this circuit is equivalent to the old circuit if proper values of resistance for a b and c are used

8. Jul 3, 2017

### vishnu 73

i dont understand what formula that is

9. Jul 3, 2017

### lewando

This is the formula for finding the equivalent resistance of 3 resistors in parallel. Not the delta-wye formula.