GATE-2018 (24) :Wyllie – Time average equation

CSIR-NET

55. The curve joining the points of the least geomagnetic field intensity on the Earth's surface is

A) an isopore

B) an isogone

C) the magnetic meridian

D) the magnetic equator

Answer: D

Explanation:

Element of magnetic maps:

(i) Isogonic lines: There are the lines joining the place of same declination.

(ii) Agonic lines: These are the lines joining the places of zero declination.

(iii) Isoclinic lines: These are the lines joining the points of equal dip.

(iv) Actinic lines or magnetic Equator: These are the lines joining the points of zero dip.

(v)Isodynamic lines: these are the lines joining the places of equal ‘H’

Reference: https://blog.myrank.co.in/magnetic-maps-and-neutral-points/