Two identical current carrying coaxial loops, carry current I in an opposite sense. A simple amperian loop passes through both of them once. Calling the loop as C,
(a)
(b) the value of is independent of sense of C
(c) there may be a point on C where, B and dl are perpendicular
(d) B vanishes everywhere on C
The correct answers are the options (b, c).
In case of the given current distribution, Ampere’s law states another method to calculate the magnetic field.