Question:
The magnetic field of the earth can be modelled by that of a point dipole placed at the centre of the earth. The dipole axis makes an angle of 11.3o with the axis of the earth. At Mumbai, declination is nearly zero. Then,
(a) the declination varies between 11.3o W to 11.3o E
(b) the least declination is 0o
(c) the plane defined by dipole axis and the earth axis passes through Greenwich
(d) declination average over the earth must be always negative
Solution:
(a) the declination varies between 11.3o W to 11.3o E