(a) Pattern D
Reason — Pattern D shows uniform magnetic field lines because it contains parallel, equally spaced straight lines indicating a uniform magnetic field.
(b) Pattern A
Reason — The pattern for the magnetic field around a straight current carrying wire is concentric circles around it which is shown in pattern A. So, A shows pattern of magnetic field for a straight current carrying wire.
(c) Pattern B
Reason — In pattern B, magnetic field lines are emerging from the loop and curving which is equivalent to a circular current carrying loop. So, B shows pattern depicted by current in a loop.
