Magnetism And Matter

Question

(a) Draw diagrams to depict the behaviour of magnetic field lines near a ‘bar’ of:
(i)    copper
(ii)    aluminium
(iii) mercury, cooled to a very low temperature (4.2 K)
(b) The vertical component of the earth's magnetic field at a given place is $\sqrt{3}$ times its horizontal component. If total intensity of earth's magnetic field at the place is 0.4 G find the value of:
(i)    angle of dip
(ii) the horizontal component of earth's magnetic field.

Solution

(a)
(i) Copper is a diamagnetic material. When a specimen of a diamagnetic material is placed in a magnetising field, the field lines are repelled and the field inside the material is reduced.

(ii) Aluminium is a paramagnetic material. When a specimen of a paramagnetic material is placed in a magnetising field, the magnetic field lines prefer to pass through the specimen rather than through air.

(iii) Mercury at a very low temperature (4.2 K) is diamagnetic material. The magnetic field lines are shown as

(b)
Here,
Vertical component is

\sqrt{3}

times the horizontal field.
And, B is the total intensity of earth's magnetic fiekd.
i.e.,

B_{V} = \sqrt{3} B_{H} and B = 0.4 G

(i)

\tan δ = \frac{B_{V}}{B_{H}}

\tan δ = \frac{\sqrt{3} B_{H}}{B_{H}} = \sqrt{3}

\tan δ = \tan 60 ° \Rightarrow δ = 60 °

∴

Angle of dip =

60 °

(ii) Horizontal component of earth's magnetic field
B_H = B cos δ
H = 0.4 cos 60°
$= 0.4 \times \frac{1}{2} = 0.2 G$

Some More Questions From Magnetism and Matter Chapter

Answer the following question:
The earth's magnetic field varies from point to point in space. Does it also change with time? If so, on what time scale does it change appreciably?

Answer the following question:
The earth's core is known to contain iron. Yet geologists do not regard this as a source of the earth's magnetism. Why?

Answer the following question:
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?

Answer the following question:
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?

Answer the following question:
The earth’s field departs from its dipole shape substantially at large distances (greater than about 30,000 km). What agencies may be responsible for this distortion?

For Daily Free Study Material Join wiredfaculty

Magnetism And Matter

Some More Questions From Magnetism and Matter Chapter

Answer the following question:
The earth's magnetic field varies from point to point in space. Does it also change with time? If so, on what time scale does it change appreciably?

Answer the following question:
The earth's core is known to contain iron. Yet geologists do not regard this as a source of the earth's magnetism. Why?

Answer the following question:
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?

Answer the following question:
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?

Answer the following question:
The earth’s field departs from its dipole shape substantially at large distances (greater than about 30,000 km). What agencies may be responsible for this distortion?

Mock Test Series

NCERT Sample Papers

Entrance Exams Preparation

Phone Number

Email Address

Loaction

For Daily Free Study Material Join wiredfaculty

Magnetism And Matter

Some More Questions From Magnetism and Matter Chapter

Answer the following question:The earth's magnetic field varies from point to point in space. Does it also change with time? If so, on what time scale does it change appreciably?

Answer the following question:The earth's core is known to contain iron. Yet geologists do not regard this as a source of the earth's magnetism. Why?

Answer the following question: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?

Answer the following question: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?

Answer the following question:The earth’s field departs from its dipole shape substantially at large distances (greater than about 30,000 km). What agencies may be responsible for this distortion?

Mock Test Series

NCERT Sample Papers

Entrance Exams Preparation

Answer the following question:
The earth's magnetic field varies from point to point in space. Does it also change with time? If so, on what time scale does it change appreciably?

Answer the following question:
The earth's core is known to contain iron. Yet geologists do not regard this as a source of the earth's magnetism. Why?

Answer the following question:
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?

Answer the following question:
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?

Answer the following question:
The earth’s field departs from its dipole shape substantially at large distances (greater than about 30,000 km). What agencies may be responsible for this distortion?