What are the advantages of an electromagnet over a permanent magnet
Answers
Here is your answer :
⇒ The permanent magnet does not have electric current flow through it.
⇒ Electromagnets are made by passing electric current through it.
⇒ The strength of the magnetic field in permanent magnets cannot be changed.
⇒ The strength of the electromagnets can be changed by changing the amount of current in the magnet.
⇒ The direction of the magnetic field cannot be changed.
⇒ The direction of magnetic field can be changed in electromagnets.
⇒ The polarity of permanent magnets cannot be changed.
⇒ The polarity of the electromagnets can be changed.
Thus electromagnet is better !
The advantages of an electromagnet over a permanent magnet are as follows :
1. In an electromagnet, strength can be changed by changing the current through the coil, but in a Permanent magnet, its strength is fixed.
2. In an electromagnet, Polarities can be reversed by changing the direction of the current, but in a Permanent magnet, polarities are fixed.
3. Electromagnet can be demagnetized immediately by stopping the current flow in the coil, but a Permanent magnet, Cannot be immediately demagnetized.
How to make an electromagnet?
- A soft iron core is taken to make an electromagnet, and an insulated copper wire is wound over it.
- The two ends of it are connected to a battery and a key.
- The electromagnet gets demagnetized when the key is removed.
Uses of an electromagnet :
- Strong electromagnets are used in cranes to lift cars and other vehicles.
The strength of the electromagnet depends upon:
(i) Number of turns:
The strength of the electromagnet is directly proportional to the number of turns.
(ii) Current flowing:
Larger the current flowing through the wire, the stronger the electromagnet
(iii) Length of the air gap:
Lesser the length of the air gap between poles, the stronger the electromagnet.
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