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. [2024]
B and D only
A and C only
A, C and D only
C only
(2)
The strong magnetic pole will attract the magnet, so force is needed to hold the sheet if it is conducting.
If the sheet is conducting and moved away from the pole, magnetic flux changes due to which eddy currents are induced.
So, the force is needed to move the sheet away from the pole with uniform velocity.
In which of the following devices, the eddy current effect is not used? [2019]
electric heater
induction furnace
magnetic braking in train
electromagnet
(1)
Electric heater works on the principle of Joule’s heating effect.
