Q. An equilateral triangle is made by uniform wires current enters at and leaves from the mid point of . If the lengths of each side of the triangle is , the magnetic field at the centroid of the triangle is Physics Question Image

 5071  289 WBJEEWBJEE 2013Moving Charges and Magnetism Report Error

Solution:

The given situation can be shown as
image
The magnetic field at centroid Magnetic field due to left part + Magnetic field due to right part
direction of B due to both parts is different of )