The use of eddy currents is done in the following,except:

$A$ metallic ring connected to a rod oscillates freely like a pendulum. If now a magnetic field is applied in a horizontal direction so that the pendulum now swings through the field,the pendulum will

$A$ metal sheet is placed in a magnetic field that changes from zero to maximum. If the figure shows the direction of eddy currents,then the direction of the magnetic field is:

$A$ magnet is dropped down an infinitely long vertical copper tube.

The small energy losses in transformers due to eddy currents can be reduced by

$A$ coil is suspended in a uniform magnetic field,with the plane of the coil parallel to the magnetic lines of force. When a current is passed through the coil,it starts oscillating; it is very difficult to stop. However,if an aluminium plate is placed near the coil,it stops. This is due to: