A light disc made of aluminium (a nonmagnetic material) is kept horizontally and is free to rotate about its axis as shown in the figure. A strong magnet is held vertically at a point above the disc away from its axis. On revolving the magnet about the axis of the disc, the disc will (figure is schematic and not drawn to scale)

Question

A light disc made of aluminium (a nonmagnetic material) is kept horizontally and is free to rotate about its axis as shown in the figure. A strong magnet is held vertically at a point above the disc away from its axis. On revolving the magnet about the axis of the disc, the disc will (figure is schematic and not drawn to scale) (A) rotate in the direction opposite to the direction of magnet’s motion (B) rotate in the same direction as the direction of magnet’s motion (C) not rotate and its temperature will remain unchanged (D) not rotate but its temperature will slowly rise

Tardigrade Admin · Accepted Answer

<img class="img-fluid question-image" alt="image" src="https://cdn.tardigrade.in/img/question/physics/a531bdb4b670e5dfc77f5ce2937cc2b2-.png" /> otimes is decreasing, so clockwise current in the square loop is induced. So force (along the arrow) is acting on the disc. So movement of disc is along the direction of motion of magnet.

rotate in the direction opposite to the direction of magnet’s motion

rotate in the same direction as the direction of magnet’s motion

not rotate and its temperature will remain unchanged

not rotate but its temperature will slowly rise

⊗ is decreasing, so clockwise current in the square loop is induced. So force (along the arrow) is acting on the disc. So movement of disc is along the direction of motion of magnet.

$\otimes$ is decreasing, so clockwise current in the square loop is induced.
So force (along the arrow) is acting on the disc.
So movement of disc is along the direction of motion of magnet.