# Is magnetic field always circular?

I want to ask if magnetic field lines are always circular and If YES , Then WHY ??? Or on What basis we can say that magnetic field lines are always circular ?? I am confused with the topic . It is my humble request to help me out if you can . I am waiting for your answer . I shall be highly obliged to you if you clear this doubt .

• Only the magnetic field lines surrounding a linear current carrying wire are circular. Other more general currents produce field lines of a more general shape. For example, inside a current carrying coil the field lines are mostly linear. – Lewis Miller Aug 15 '16 at 14:52
• @ Lewis Miller , What is a linear current carrying wire ???? Please explain . – Apurwa Aug 15 '16 at 15:02
• A linear current carrying wire is a straight wire with a current running through it, like the image on the left below. The image on the right is one example of a current carrying coil (although really it's a ring not a coil). – Ulthran Aug 15 '16 at 15:43

• Yes, and the reason why is $\nabla\cdot B=0$. You could have magnetic field lines terminate at a point only if you had a magnetic monopole. – EL_DON Aug 15 '16 at 15:58