A compas needle will show which of the following directions at the earth's magnetic pole?

To find the direction of the magnetic field produced by a current -carrying wire, a magnetic needle is placed at different positions as shown in the following figure . Which position of the magnetic needle corresponds to the correct direction of the magnetic field ?

Assertion (A): Compass needle points the magnetic north-south direction. Reason (R): The magnetic meridian of the earth merges with the axis of rotation of earth.

The earth's magnetic field is approximately like that of a giant magnetic dipole, whose axis is inclined roughly 20^@ west of the axis of rotation of earth which is the geographic N-S direction. The strength of earth's magnetic field is of the order of 10^-4 tesla . Three magnetic elements of earth are: Magnetic declination (theta) , magnetic inclination or magnetic dip (delta) and horizontal component (H) of earth's magnetic field. Magnetic declination is the small angle between magnetic axis and geographic axis at a place. Magnetic dip at a place is the angle, which the direction of total strength of earth's magnetic field (R) makes with a horizontal line in magnetic meridian. If H is horizontal component and V is vertical component of earth's magnetic field, then H=Rcos delta , V=Rsin delta and R=sqrt(H^2+V^2) . At a place on the surface of earth. H is of the order of 3*3xx10^-5tesla . At magnetic poles, a compass needle points out

If a traveller using a compass needle follows the direction of the magnetic needle, would be able to reach the geographic north pole ? Explain in detail.

Assertion: A compass needle when placed on the magnetic north pole of the earth rotates in vertical direction. Reason: The earth has only horizontal component of its magnetic field at the north poles.

Assertion: A compass needle when placed on the magnetic north pole of the earth rotates in vertical direction. Reason: The earth has only horizontal component of its magnetic field at the north poles.

A magnetic needle suspended by a silk thread is vibrating in the earth's magnetic field. If the temperature of the needle is increases by 500^(@) C , then