Tag: magnetic field of earth

Questions Related to magnetic field of earth

The place where the angle of dip is 90 are known as

  1. Geographical poles of the earth

  2. Magnetic equator

  3. Magnetic poles of the earth

  4. None of the above


Correct Option: C
Explanation:

Angle of dip at a point on earth is the angle between earth's magnetic field at given point and the horizontal line of magnetic meridian.

Since the magnetic lines of force emerge and terminate at the poles of Earth, the magnetic lines of force at the poles are perpendicular to the surface there. Hence the angle of dip is $90^{\circ}$.

The north pole of earth's magnet is near

  1. Geographic north

  2. At the center of earth

  3. Geographic south

  4. In any direction


Correct Option: C
Explanation:

Keep this well in mind that the magnetic poles are opposite in position as the geographic poles.

Magnetic north is at geographic south and vice versa.
Geographic north is the part which includes Greenland and south is Antartica.
When we hang a bar magnet then its poles are attracted to the opposite magnetic poles of the earth. We know that opposite poles attract each other.
That's the reason why the bar's north pole turns towards the geographic north of the earth and the south to south.

The earth's field departs from its dipole shape substantially at large distance (greater than about $3000$ km). The responsible factor for this distortion is then

  1. motion of ions in earth's ionosphere

  2. motion of ions in earth's atmosphere

  3. motion of ions in earth's lithosphere

  4. motion of ions in the space.


Correct Option: A
Explanation:

Due to motion of ions in earth's ionosphere the earth's magnetic field gets modified.