$A$ 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:

$A$ sheet is placed on a horizontal surface in front of a strong magnetic pole. $A$ force is needed to:
$A$. hold the sheet there if it is magnetic.
$B$. hold the sheet there if it is non-magnetic.
$C$. move the sheet away from the pole with uniform velocity if it is conducting.
$D$. move the sheet away from the pole with uniform velocity if it is both,non-conducting and non-polar.
Choose the correct statement$(s)$ from the options given below:

$A$ hollow metal pipe is held vertically and a bar magnet is dropped through it with its length along the axis of the pipe. The acceleration of the falling magnet is ($g=$ acceleration due to gravity).

$A$ copper ring is held horizontally and a bar magnet is dropped through the ring with its length along the axis of the ring. The acceleration of the falling magnet while it is passing through the ring is

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

The working of magnetic braking of trains is based on