Answer:
a) The lines of magnetic field round a straight current-carrying conductor are in the shape of concentric circles.
Explanation:
![](https://www.learnatnoon.com/s/in//wp-content/uploads/sites/8/2021/09/image-1125.png)
b) For a current-carrying solenoid, the magnetic field is like that of a bar magnet.
Explanation:
The magnetic field pattern created by a current-carrying solenoid is similar to the pattern produced by a bar magnet.