Question

Earth’s magnetic strength is __________ near the geographical poles.
(A) Strongest
(B) Weakest
(C) Zero
(D) None of the above

Answer 1

Hint Magnetic lines in a magnet start from the north magnetic pole to the south magnetic pole. You can think of the earth’s pole as the pole of a magnet. Thus, the higher the flux of the magnetic field can be observed near the pole as compared to anywhere else on the planet.

Complete Step by step solution
Earth’s magnetic strength is strongest near the geographical poles. Like a magnet bar, the earth’s magnetic lines loops going from the north magnetic pole to south magnetic. The magnetic field lines are closer near the poles comparatively and it goes into space and back to the south pole of the earth. The field is comparatively weaker near the equator.
Geographically, it is accepted that the origin of the earth’s magnetic field is the electric current that flows in the molten outer core of Earth.

Thus, Option (A) is correct.

Additional Information The magnetic field can be calculated. It has been approximated correctly centuries ago. However, now we can represent the earth’s magnetic field by the following diagram:
 

Here, the X-axis represents the geographic north while the Y-axis represents the geographic east.
The Z-axis points towards the downward direction.
The inclination or magnetic inclination is the angle between horizontal and earth’s magnetic field. The way it is measured is that positive values suggest that the magnetic field is pointing downwards while the negative value means the magnetic field is pointing upwards. This angle varies with the position of the observer on earth.
Declination of Magnetic declination is the angle between geographic north and true (magnetic) north. Like the magnetic inclination, this angle also varies with the position of the observer.

Note Take care of the fact that the geographic North pole of the earth is the magnetic south pole. In the case of compasses, the opposites attract, and thus the north end of the compass needle points towards the magnetic south. While approaching such a question, take care of what has been asked, geographic north/south pole, or magnetic north/south pole.