Let the magnetic field on earth be modelled by that of a point magnetic dipole at the centre of earth. The angle of dip at a point on the geographical equator

Options

A. is always zero
B. can be zero at specific points
C. can be positive or negative
D. is bounded

Answer

B, C, D

Explanation

1) Angle of dip is zero only at the magnetic equator.
2) It is self-explanatory in the light of (1).
3) In most of the northern hemisphere, the north pole of the dip needle tilts downwards and like wise in the southern hemisphere, the south pole of the dip needle tilts downwards.
4) It is self-explanatory in the light of (3).
Options (2,3,4) are satisfied by the angle of dip at a point on the geographic equator.