# Homework Help: Find the magnetic induction

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1. Mar 23, 2016

1. The problem statement, all variables and given/known data
Three parallel wires are put in the angles of an equilateral triangle with sides 14 cm. The values of the currents are 10A,10A, 20A and the first and third are in different directions. Find the magnetic induction in the center of the triangle

2. Relevant equations
B=I*μ0/2*pi*d

3. The attempt at a solution
B1=B2=2.5*10^-5T
B3=5*10^-5T. I don't know which of these cases should I consider based on the problem's information.
Could you tell me which is right so I can continue with the sketch of induction?
http://postimg.org/image/4aco9wajl/

2. Mar 23, 2016

### BvU

Doesn't matter for the magnitude. Do all four if you don't believe me,,,,,

3. Mar 24, 2016

So here's what I did. http://postimg.org/image/8licrhc1f/
B12=2.5*10^-5T (as the angle is 120 degress), B3=5*10^-5 T. As they are opposite vectors. (5-2.5)*10^-5=2.5*10^-5 T.

4. Mar 24, 2016

### BvU

Check the direction of B3.

Reason for this suspicion: I what would be the situation if all three currents were in the same direction and of equal magnitude ?

5. Apr 12, 2016