How Is Magnetic Induction Calculated in a Triangle of Parallel Wires?

[zade70]

Homework Statement

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

Homework Equations

B=I*μ0/2*pi*d

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/

 

[BvU]

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

 

[zade70]

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

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.

 

[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 ?

 

[zade70]

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 ?

http://postimg.org/image/npe8682kp/
I corrected it.
The formula:
B=I*μ0/2*pi*d
B1=B2=2.4743*10^-5 T
B3=4.9486*10^-5 T
B=B12+B3=7.423 -10^-5 T, but the solution is 5.1*10^-5 T.