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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
You are given the magnetic field pattern of a magnet. How will you find out from it where the magnetic field is the strongest?
Fill in the following blank with suitable words:
The lines of ........... round a straight current-carrying conductor are in the shape of ...........
A magnetic field exerts no force on:
an electrical charge moving perpendicular to its direction
an unmagnetised iron bar
a stationary electric charge
a magnet
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?
A portable radio has a built-in transformer so that it can work from the mains instead of batteries. Is this a step-up or step-down transformer?
Complete the following sentence :
If the field lines in a magnetic field are parallel and equidistant, the magnetic field is __________ .
State briefly the molecular theory of magnetism.
Describe two methods of determining the arrangement of the lines of force in the field close to a bar magnet. Give a brief explanation of each method.
The relative strength of the magnetic field at a point in the space surrounding the magnet is shown by the ____________.
