Answer the following questions regarding earth's magnetism.  (a) A vector needs three
Channel: Doubtnut
Date: 2020-08-02

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^@`. Would you expect a greater or lesser 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) Which direction would a compass needle 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 `8xx10^(22)JT^-1` located at its centre. Check the order of magnetude 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?