In Fig, find the magnetic field at point P. The loop is lying in x-y plane.

Explanation

Magnetic field due to circular loop, `vecB_1=(mu_0i)/(2a) (120^@)/(360^@) (hatk)=(mu_0i)/(6a)hatk`.
Due to straight wire,
`vecB_2=(2mu_0i)/(4pia) xx2sin60(-hatk)=(sqrt3)/2 (mu_0i)/(pia)(-hatk)`
`:. vecB_(n et)=(sqrt3)/2 (mu_0i)/(pia)(-hatk)+ (mu_0i)/(6a)(hatk)=(mu_0i)/(2pia)(sqrt3-pi/3)(-hatk)`