Q) A steel bar can be permanently magnetised:
(a) by placing it in contact with a bar magnet for an hour
(b)by rubbing bar magnet along its length
(c) by rubbing the bar magnet at its ends
(d) by rubbing the bar magnet at its centre
(a) by placing it in contact with a bar magnet for an hour
(b)by rubbing bar magnet along its length
(c) by rubbing the bar magnet at its ends
(d) by rubbing the bar magnet at its centre
Answers & Comments
c
The rubbing magnets are then lifted off the surface of the steel bar and placed back in the center of the bar. This whole process is repeated again and again as shown. The steel bar thus magnetized becomes a permanent magnet but the degree of magnetization is very low
Answer:
Q) A steel bar can be permanently magnetised:
(b) by rubbing bar magnet along its length .