Question

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. B and D only
• B. A and C only
• C. A, C and D only
• D. C only

Answer 1

The Correct Option is B

A sheet is positioned on a horizontal surface before a powerful magnetic pole. A force is required to:

A. Maintain the sheet's position if it is magnetic.

B. Maintain the sheet's position if it is non-magnetic.

C. Displace the sheet from the pole at a constant velocity if it is conducting.

D. Displace the sheet from the pole at a constant velocity if it is both non-conducting and non-polar.

Select the accurate statement(s) from the provided options:

Explanation:

A. Accurate. A magnetic sheet will experience attraction to the magnetic pole, necessitating an opposing force for stabilization.

B. Inaccurate. A non-magnetic sheet will not be attracted to the magnetic pole, thus no force is needed to hold it stationary.

C. Accurate. When a conducting sheet is moved away from the pole, the alteration in magnetic flux induces eddy currents. These currents generate a force that opposes the movement.

D. Inaccurate. A non-conducting and non-polar sheet will not exhibit induced eddy currents and will be negligibly affected by the magnetic field, requiring no external force for uniform velocity movement.

Conclusion:

Statements A and C are correct.