Magnetic field at center of wire

[cupid.callin]

Homework Statement

The Attempt at a Solution

how i did was that i consider the two negative currents flowing through two drills ... and let current from the original wire is out of plane

so on first drill mag field will be towards left (field by original wire at its center is 0)

as after second drill , current density remains same and area dec ... so current also dec.

now the field due to new line will be perpendicular to line joining its center ... so field at center shall inc ... its not the answer

 

[cupid.callin]

Oh ... solved it ... both field will have 120 angle ...

so net will remain same ... :p