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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.
उत्तर
Aim: To make an electromagnet.
Materials Required: An iron nail, a battery, a switch, some insulated copper wire, and some iron paper pins.
Procedure: Coil the insulated copper wire around the iron nail. Connect the ends of the wire to the battery through the switch. Close the switch so that electric current flows through the copper wire. Now bring the iron paper pins close to the iron nail.
Observation And Conclusion: The paper pins get attracted to the nail, showing that the nail has turned into an electromagnet. Now, if you switch off the current, the iron paper pins will drop off the iron nail.
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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?
State three uses of an electromagnet?
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 purpose of the iron core.
State the condition when an electric charge can give rise to a magnetic field.
State the principle of a D. C. motor.
The primary windings of a step-up transformer are usually made of thicker wire than the secondary. Explain.
(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.
