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प्रश्न
What energy conversion takes place during the working of a d c motor?
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उत्तर
Electrical energy to mechanical energy.
संबंधित प्रश्न
The diagram shows a coil wound around a U shape soft iron bar AB.
1) What is the polarity induced at the ends A and B when the switch is pressed?
2) Suggest one way to strengthen the magnetic field in the electromagnet
3) What will be the polarities at A & B if the direction of current is reversed in the circuit?
Tick the most appropriate answer.
Which of the following methods is used to magnetize a magnetic without touching it by a magnet?
Name two factors on which the strength of magnetic field of an electromagnet depends and state how does it depend on the factors stated by you.
State two differences between an electromagnet and a permanent magnet.
Name the material used for making the armature of an electric bell. Give a reason for your answer.
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 ______.
Complete the following sentence :
On reserving the direction of current in a wire, the magnetic field produced by it gets _____.
State the position of armature coil relative to the direction of magnetic field, in a D. C. motor when the deflecting couple acting an the coil is maximum.
Point out three differences between an electromagnet and a bar (or permanent) magnet.
(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.
