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 magnitude of this number in some way.

Answer the following questions regarding earth's magnetism. a. A vector needs three 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 smaller dip angle in Britain ? c. If you made a map of magnetic field lines at Melboune in Australia, would the lines seem to go into the groung 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 xx10^(22)JT^(-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 ?

The earth's magnetic field at the equator is approximately 0.4 G. Estimate the earth's dipole moment.

Find the magnetic field due to a dipole of magnetic moment 1.2 A m^2 at a point 1m away from it in a direction making an angle of 60^@ with the dipole-axis .

An electric dipole of charges 2 xx 10^-6C, -2xx10^-6C are separated by a distance 1 cm. Calculate theelectric field due to dipole at a point on its. (i) axial line 1 m from its centre (ii) equatorial line 1 m from its cnetre.

A short bar magnet placed with its axis at 30^@ with an external field of 0.25 T experiences a torque of magnitude to 4.5xx10^(-2)J . What is the magnitude of magnetic moment of the magnet ?

A magnetised needle of magnetic moment 3.6 xx 10^(-2) T^(-1) is placed at 30^(@) with the direction of uniform magnetic field of magnitude 2 xx 10^(-2)T . Calculate the torque acting on the needle.

A current - carrying circular coil of 100 turns and radius 5.0 cm produces a magnetic field of (6.0 xx 10 ^-5) T at its centre. Find the value of the current.

The horizontal component of the earth's magnetic field is 3.6 xx 10^(-5) T where the dip is 60^@ . Find the magnitude of the earth's magnetic field.

An electrle dipole with dipole moment 4 xx 10^(-9)Cm is aligned at 30^@ with the direction of a uniform clectric field of magnitude 5 xx 10^(4)NC^(-1) Calculate the magnitude of the torque acting on the dipole.

If the solenoid in is free to turn about the vertical direction and a uniform horizontal magnetic field of 0.25T is applied , what is the magnitude of torque on the solenoid when its axis makes an angle of 30^@ with the direction of applied field ? Given magnetic moment 0.6 JT −1 .