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प्रश्न
State two factors on which the strength of induced e. m.f. depends.
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उत्तर
(i) The time of change of magnetic flux, (ii) The strength of magnetic field.
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संबंधित प्रश्न
You are given an iron nail, a torch cell, and a long piece of insulated copper wire. With the help of a labelled neat diagram, describe in steps how you will make the nail, an electromagnet.
Show with the aid of a diagram how a wire is wound on a U-shaped piece of soft iron in order to make it an electromagnet. Complete the circuit diagram and label the poles of the electromagnet.
Fill in the blanks by writing (i) Only soft iron, (ii) Only steel, (iii) Both soft-iron and steel for the material of core and/or magnet.
Electric bell ______.
Describe briefly one way of producing an induced current in a coil. State one factor that determines the magnitude of induced e.m.f.
How does a magnetic field set up by a solenoid change when a soft iron core is inserted inside solenoid?
State two advantages of an electromagnet over a bar magnet.
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What energy conversion takes place during the working of a d c motor?
State the principle of a D. C. motor.
(i) A straight wire conductor passes vertically through a piece of cardboard sprinkled with iron filings. Copy the diagram and show the setting of iron filings when a current is passed through the wire in the upward direction and the cardboard is tapped gently. Draw arrows to represent the direction of the magnetic field lines.
(ii) Name the law which helped you to find the direction of the magnetic field lines.
