Question
When a compass needle be placed at magnetic north pole, how would it behave? If a dip needle be placed at the place, how would it behave?
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Answer
Compass needle stays in horizontal north-south direction. At poles horizontal component H = 0; therefore there will be no effect of earth’s field on magnetic north pole and it can stay in any direction; on the other hand a dip needle points along the resultant magnetic field and at poles the resultant field is vertical; hence the needle becomes vertical.
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