Explaing the source of earth magnetism.

Answer the following questions . a. The earth's magnetic field varies from point is space. Does it also change with time ? It so , on what time scate does it change appreciably ? b. The earth's core is known to contain iron. Yet geologists do not regard this as a source of the earth's magnetism why ? c. The charged currents in the outer conducting regions of the earth's core are thought to be responsible for earth's magnetism . What might be the ' battery ' (i.e., the source of energy) to sustain these currents ? d. The earth may have even reversed the direction of its field several times during its history of 4 to 5 billion years. How can geologists know about the earth's field in such distant past ? e. The earth's field departs from its dipole substantially at large distances (greater than about 30,000 km) what agencies may be responsible for this distortion ? f. Interstellar space has an extremely weak magnetic field of the order of 10^(-12) T, Can such a weak field be of any significant consequence ? Explain. [Note : Exercise 2 is meant mainly to arouse your curiosity . Answers to some question above are tentative or unknown . Brief answers wherever possible are given at the end . For details , you should consult a good text on geomagnetism.]

Write a note on Earth's magnetism.

What are the causes for earth's magnetic field according to Gover ?

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.

A capacitor is connected to an alternating- current source. Is there a magnetic field between the plates ?

The frequency of oscillation of the magnet in an oscillation magnetometer in the earth's magnetic field is 40 oscillations per minute. A short bar magnet is placed to the north of the magnetometer, at a separation of 20cm from the oscillating magnet, with its north pole pointing towards north (figure). The frequency of oscillation is found to increase to 60 oscillations per minute. Calculate the magnetic moment of this short bar magnet. Horizonatl component of the earth's magnetic field is 24 muT .

A short magnet produces a deflection of 37^@ in a deflection magnetometer in Tan-A position when placed at a separation of 10cm from the needle. Find the ration of the magnetic moment of the magnet to the earth's horizontal magentic field.

State the elements of Earth's magnetic field .

At a place, the horizontal component of earth's magnetic field is B and angle of dip is 60^(@) . What is the value of horizontal component of the earth's magnetic field at equator ?

a. Where on the earth's surface is the value of vertical component of the earth's magnetic field zero ? b. The horizontal component of the earth's magnetic field at a given place is 0.4xx10^(-4) Wb//m^2 and angle of dip is 30^@ Calculate the value of (i) vertical component (ii) the total intensity of the earth's magnetic field.