Question

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,

Options:
(a) ` ∫_cÑ B.dl = m2 μ_0 I` .
(b) the value of ` ∫_0 ÑB.dl` 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.