What are the Earth magnetic elements defined ? And which are they ?
To obtain the complete information about the Earth's magnetic field and its value and its direction at any place on the surface of the Earth three magnetic elements are defined. They are :
$(1)$ Magnetic declination : $(D)$
$(2)$ Magnetic dip angle: $(I)$
$(3)$ Two components of Earth's magnetic field.
$(a)$ Horizontal component $\mathrm{H}_{\mathrm{E}}$ and
$(b)$ Vertical component $Z_{\mathrm{E}}$
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?
At a place, the horizontal and vertical intensities of earth's magnetic field is $0.30$ Gauss and $0.173$ Gauss respectively. The angle of dip at this place is.....$^o$
Magnetic meridian is a
A current carrying coil is placed with its axis perpendicular to $N-S$ direction. Let horizontal component of earth's magnetic field be $H_0$ and magnetic field inside the loop be $H$. If a magnet is suspended inside the loop, it makes angle $\theta $ with $H$. Then $\theta =$
A long vertical wire carries a steady current of $5.0 \,A$. Asensitive magnetic compass is placed in a plane perpendicular to the wire and $10.0$ $cm$ south of it. It registers a deflection $60^{\circ}$ north of east. The magnitude of the horizontal component of the earth's magnetic field is (permeability of free space is $4 \pi \times 10^{-7} \,N/A{ }^2$ )