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प्रश्न
State two advantages of an electromagnet over a bar magnet.
उत्तर
Electromagnet can produce a strong magnetic field. Its polarity can be changed by reversing the direction of current.
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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?
What is an electromagnet?
What is an electric motor?
Name the material of core in (a) an electric bell, (b) electromagnet, (c) a d.c. motor, (d) an a.c. generator and (e) a transformer.
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 ______.
State two factors on which the strength of induced e. m.f. depends.
How does a magnetic field set up by a solenoid change when strength of current in the solenoid is decreased?
State the factors, on which depends the magnitude of the force acting on current carrying conductor, when it is kept in a magnetic field perpendicular to it.
Point out three differences between an electromagnet and a bar (or permanent) magnet.
Write the answer in your word.
How is an electromagnet made?
