IIT JEE , AIEEE Forum - Physics , Magnetism

rakesh61

29. The dip at earth?s poles

(A) can only be 0 o

(B) cannot be less than 90 o

(C) can only be 90 o

(D) cannot be greater than 90 o

(E) varies between 0 o and 90 o since the earth rotates

about its axis

Ans is given E bt i think it will be A rates assured

suresan

If the question is about the dip at the geographic poles then answer E is right.

annihilator

Suresan is right the magnetic axis of earth do not coincide with the geographic one (its sligtly tilted)and hence as earth rotates the value of dip varies

cyborg

The dip wud have been 90⁰at the magnetic poles

(since the field lines are all pointing into the ground)

but since the magnetic axis of the earth is inclined to the geographic axis , the corresponding poles wud also be different .

So in the geographic poles , the dip wud be close to 90⁰ but not quite that.

PS: Dip becomes 0 at the equator since the magnetic field lines are parallel to the ground.

eistien

hey there are two reasons

one that magnetic poles and geographic poles do not coincide

the other being that the earth is a effective magnet made up of small tiny dipoles now due to constantly changing conditions in the core of earth the pole position keeps changing slightly and therefore you should always say only between 0 and 90!!!

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