A current carrying loop lies on a smooth horizontal plane. Then,

Options

A. it is possible to establish a uniform magnetic field in the region so that the loop starts rotating about its own axis.
B. it is possible to establish a uniform magnetic field in the region so that the loop will tip over over about any of the point.
C. it is not possible that loop will tip over about any of the point whatever be the direction of established magnetic field (uniform).
D. both (a) and (b) are correct.

Answer

b

Explanation

As the loop is placed in horizontal plane, so area vector is along vertical direction. From `vectau=I(vecAxxvecB)`, as `vecA` is in vertical direction, `vectau` would be the plane of loop only. So, option (a) is wrong because for rotation of loop about its own axis `vectau` must be along vertical direction. (b) is correct because we can produce torque in the plane of the loop and due to this the loop can tip over.