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प्रश्न
How do you account for the following fact?
Soft iron keepers help to prevent the magnets from losing their magnetic properties.
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उत्तर
In magnets, external fields like earth’s magnetic field can randomize the domains. Perhaps stray fields caused by flowing currents in nearby electric circuits can also disturb i the alignment of domains lying inside a magnet. Given enough time, such magnets may find their domains randomly oriented and hence their net magnetisation may get lost. A keeper for magnets is just a strong permanent magnet that keeps all the domains pointing the same way and realign those that may have gone astray and hence magnet, can retain its magnetism for a long time.
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संबंधित प्रश्न
Fill in the following blank with suitable words:
The earth's magnetic field is rather like that of a .......... magnet with its .......... pole in the northern hemisphere.
A strong bar magnet is placed vertically above a horizontal wooden board. The magnetic lines of force will be:
(a) only in horizontal plane around the magnet
(b) only in vertical plane around the magnet
(c) in horizontal as well as in vertical planes around the magnet
(d) in all the planes around the magnet
The shape of the earth's magnetic field resembles that of an imaginary:
(a) U-shaped magnet
(b) Straight conductor carrying current
(c) Current-carrying circular coil
(d) Bar magnet
Explain the following :
When two pins are hung by their heads from the same pole of a magnet, their pointed ends moves apart.
Draw the pattern of magnetic field lines near a bar magnet placed with its North Pole pointing towards the geographic North. Indicate the position of neutral points by marking X.
State whether the magnetic field lines in part (a) represent a uniform magnetic field or non-uniform magnetic field?
Answer the following question.
Draw the pattern of magnetic field lines of
(i) a current-carrying solenoid and
(ii) a bar magnet.
List two distinguishing features between the two fields.
Draw diagram showing the arrangement of the lines of force for two magnets in line, with unlike poles facing one another.
A circular loop placed in a plane perpendicular to the plane of paper carries a current when the key is ON. The current as seen from points A and B (in the plane of paper and on the axis of the coil) is anti clockwise and clockwise respectively. The magnetic field lines point from B to A. The N-pole of the resultant magnet is on the face close to
A charge moving in a magnetic field, in a direction other than the direction of the magnetic field, experiences a force. It is called the ______ force.
