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Permanent Magnets & Electromagnets Video Lecture | Physics A- Level - A Level

FAQs on Permanent Magnets & Electromagnets Video Lecture - Physics A- Level - A Level

1. What are permanent magnets?
Ans. Permanent magnets are materials that have the ability to produce their own magnetic field and retain it even when not in the presence of external magnetic fields. They are commonly made from materials such as iron, nickel, cobalt, and certain alloys.
2. How do permanent magnets work?
Ans. Permanent magnets work based on the alignment of magnetic domains within the material. These magnetic domains are groups of atoms that have their magnetic fields aligned in the same direction. When a permanent magnet is magnetized, these domains align, creating a strong magnetic field.
3. What are electromagnets?
Ans. Electromagnets are temporary magnets created by passing an electric current through a coil of wire. The magnetic field produced by the electric current in the coil magnetizes a nearby ferromagnetic material, such as iron, which then becomes magnetized.
4. How are electromagnets different from permanent magnets?
Ans. The main difference between electromagnets and permanent magnets is that electromagnets can be turned on and off by controlling the flow of electric current, while permanent magnets always produce a magnetic field. Additionally, electromagnets can have their strength adjusted by changing the amount of current flowing through the coil, whereas permanent magnets have a fixed magnetic strength.
5. What are some common applications of permanent magnets and electromagnets?
Ans. Permanent magnets are used in various applications such as electric motors, speakers, hard drives, and refrigerator magnets. Electromagnets find application in devices like doorbells, MRI machines, electric generators, and cranes, where the ability to control the magnetic field is crucial.
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