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प्रश्न
What is a lodestone?
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उत्तर
Lodestone is an ore of iron oxide (Fe3O4). This ore attracts small pieces of iron and it sets itself along a definite direction when it is suspended freely. It is a natural magnet which was used for the navigation by the mariners.
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संबंधित प्रश्न
In the straight wire A, current is flowing in the vertically downwards direction whereas in wire B the current is flowing in the vertically upward direction. What is the direction of magnetic field:
(a) in wire A?
(b) in wire B?
Name the rule which you have used to get the answer.
A thick wire is hanging form a wooden table. An anticlockwise magnetic field is to be produced around the wire by passing current through this wire by using a battery. Which terminal of the battery should be connected to the:
(a) top end of wire?
(b) bottom end of wire?
Give reason for your choice.
The wire in Figure below is being moved downwards through the magnetic field so as to produce induced current.
(a) moving the wire at a higher speed?
(b) moving the wire upwards rather than downwards?
(c) using a stronger magnet?
(d) holding the wire still in the magnetic field?
(e) moving the wire parallel to the magnetic field lines?
Which substances are used for making electromagnets?
Select the correct option:
The magnetic strength of a bar magnet is:
What do you meant by the term pole of a magnet? Magnetically speaking, what is the difference between a piece of brass, a piece of soft iron, and a piece of lode- stone?
Distinguish between
Magnetic properties of iron and steel.
State whether true or false. If false, correct the statement.
Magnetic field lines always repel each other and do not intersect.
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

Can two magnetic lines of force intersect? Justify your answer:
