The vertical component of earth's magnetic field is zero at or The earth's magnetic field always has a vertical component except at the
Magnetic poles
Geographical poles
Every place
Magnetic equator
Tell the proper reason for the earth’s magnetic field to occur.
Dip angle are $30^o$ and $45^o$ at two different places, then ratio of horizontal component of earth magnetic field at these place will be
The angle of dip at the magnetic equator is....$^o$
Give information about Earth’s magnetism.
Answer the following questions regarding earth’s magnetism:
$(a)$ A vector needs three quantities for its specification. Name the three independent quantities conventionally used to specify the earth’s magnetic field.
$(b)$ The angle of dip at a location in southern India is about $18^o$. Would you expect a greater or smaller dip angle in Britain?
$(c)$ If you made a map of magnetic field lines at Melbourne in Australia, would the lines seem to go into the ground or come out of the ground?
$(d)$ In which direction would a compass free to move in the vertical plane point to, if located right on the geomagnetic north or south pole?
$(e)$ The earth’s field, it is claimed, roughly approximates the field due to a dipole of magnetic moment $8 \times 10^{22}\; J\, T^{-1}$ located at its centre. Check the order of magnitude of this number in some way.
$(f)$ Geologists claim that besides the main magnetic $N-S$ poles, there are several local poles on the earth’s surface oriented in different directions. How is such a thing possible at all?