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:

When a magnetic sheet is placed near a strong magnetic pole, the magnetic field exerts a force on the sheet if the sheet itself can respond to the magnetic field.

Statement A: *Hold the sheet there if it is magnetic.*
A magnetic material becomes magnetized in the external field, producing an attractive force toward the pole. To keep the sheet stationary, an external force equal in magnitude and opposite in direction to this magnetic attraction is required. Hence statement A is true.

Statement B: *Hold the sheet there if it is non‑magnetic.*
A non‑magnetic material does not develop a net magnetization in the field, so the field does not pull it toward the pole. No holding force is needed, making statement B false.

Statement C: *Move the sheet away from the pole with uniform velocity if it is conducting.*
As the conductive sheet moves through the magnetic field, changing magnetic flux through the sheet induces eddy currents (Faraday’s law). These currents create a magnetic field that opposes the motion (Lenz’s law), producing a drag force. To maintain a uniform velocity away from the pole, an external force must continuously counteract this induced drag. Therefore, statement C is true.

Statement D: *Move the sheet away from the pole with uniform velocity if it is both non‑conducting and non‑polar.*
A non‑conducting, non‑polar sheet experiences no induced currents and no magnetic attraction. Consequently, no additional force is required to move it at constant speed; the statement is false.

Putting the true statements together, the correct choice is A and C only.