Question

Difference between magnetic field lines produced by straight and circular current carrying conductor?

Answer 1

they are non uniform and uniform field lines respectively
if I am correct

Answer 2

Magnetic field lines around a circular loop:At the centre of circular wire,field lines become straight and perpendicular to the plane of coil.Right hand thumb rule is used to determine the direction of magnetic field produced due to current carrying circular wire.
Magnetic field lines due to a straight current carrying conductor:The pattern of concentric circles indicate the field lines of a magnetic field around a straight current carrying conductor.