Question 2
If the key in the arrangement (Figure) is taken out (the circuit is made open) and magnetic field lines are drawn over the horizontal plane ABCD, the lines are
(a) concentric circles
(b) elliptical in shape
(c) straight lines parallel to each other
(d) concentric circles near the point O but of elliptical shapes as we go away from it
It follows the right-hand thumb rule. Applying right-hand thumb rule, magnetic field lines drawn over the horizontal plane ABCD are concentric lines.