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प्रश्न
Name a common device that uses electromagnets.
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उत्तर
Electromagnets are used in electric bell, door alarm, motor, dynamo etc.
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संबंधित प्रश्न
Two circular coils A and B are placed closed to each other. If the current in the coil A is changed, will some current be induced in the coil B? Give reason.
Explain why, the core of an electromagnet should be of soft iron and not of steel.
Write some of the important uses of electromagnets.
Describe one experiment to demonstrate the phenomenon of electromagnetic induction.
Name and state the law which determines the direction of induced current.
or
State Fleming’s right-hand rule.
A conducting rod is moved with a constant velocity v in a magnetic field. A potential difference appears across the two ends _____________ .
A conducting square loop having edges of length 2.0 cm is rotated through 180° about a diagonal in 0.20 s. A magnetic field B exists in the region which is perpendicular to the loop in its initial position. If the average induced emf during the rotation is 20 mV, find the magnitude of the magnetic field.
The following diagram shows a fixed coil of several turns connected to a center zero galvanometer G and a magnet NS which can move in the direction shown in the diagram.
- Describe the observation in the galvanometer if
- The magnet is moved rapidly,
- The magnet is kept still after it has moved into the coil
- The magnet is then rapidly pulled out the coil.
- How would the observation in (i) of part (a) change if a more powerful magnet is used?
Fleming's left hand rule : electric current : : Fleming's right hand rule : _______
