Question

mention the shape of magnetic field lines around a current carryind straight conductor

Answer 1

The direction of the magnetic field lines of force around a conductor is given by the Maxwell’s right hand grip rule or the right handed corkscrew rule.​ ​Imagine that you are holding a current-carrying straight conductor in your right hand such that the thumb points towards the direction of current. Then your fingers will wrap around the conductor in the direction of the field lines of the magnetic field​ (See Fig.1)​. This is known as right hand thumb rule.

Answer 2

When a current flows through aconductor, it produces
a magnetic field. The shape of the magnetic field
depends on the shape of the conductor.
You need to know the shape of the magnetic field
for a straight wire (shown below) and a coil.