Introduction

The electromagnet is a combination of two words electro + magnet. The second one is clear, this is the magnet but what about first (electro)? What does it indicate electron or electricity?

Let me know about, just think? Yes, it is electricity that flows in a conductor. But now the question is why magnet is written with it? Because when electricity flows in a current-carrying conductor it produces the magnetic field. This concept you can understand from Ampere’s law.

Electromagnet in Laboratory

You may have seen and probably heard about the coil from your lab instructor.  Also, in Stewart and Gee’s experiment, we have used a circular coil to study the variation of the magnetic field. The electromagnet is different from the coil, we use coil in the electromagnet, no doubt. This is also true but to make the temporary magnet.

The magnetic field is maximum at the center of the coil and then it decreases gradually. In the above-mentioned experiment. Now let me extend this idea to the solenoid before I reach on the electromagnet concept.

The solenoid is similar to the coil, hollow from the center. But its length is more than the diameter of the rings (loop). In the solenoid, the magnetic field is totally parallel lines of the same strength. You can say a uniform magnetic field.

Magnet vs Electromagnet

Permanent magnets are made by iron, nickel or cobalt material in general. How to make a permanent magnet? When the iron piece is kept in the presence of a uniform magnetic field, it gets magnetized. The magnetization is directly proportional to the strength of the applied magnetic field.

Magnetic materials are of three types, paramagnetic, diamagnetic and ferromagnetic. Ferromagnetic materials are used for temporary and permanent magnets.

In the electromagnet case, we insert a piece of the iron in the solenoid or Helmholtz’s coil. When current passes through the wire it produces the magnetic field that magnetized the inserted material. Now, we keep both ends flat for a uniform magnetic field.

In which experiment you had used it?

Graduate students use electromagnet in the

  1. Hall effect experiment to measure the hall coefficient.
  2. The Quinck’s Tube for magnetic susceptibility

Conclusion

In conclusion, I can say that there are mainly three things (a) Coil and (b) Solenoid. The third one is an electromagnet, which we use to get the magnetic field as of our choice. It depends on the magnitude of the current, high current means a high magnetic field. From the permanent magnets, we get a constant magnetic field of fix strength.


Quiz


These questions will help you to understand more about the functioning of the electromagnet.

1. There are two sources

  1. 220 volts 5 Amp
  2. 220 volts 8 Amp

An electromagnet is connected with these two sources, the electromagnetic field strength will be higher when it will be connected with

 
 

2. The strength of the magnetic field produced by the electromagnet does not change by changing the applied current.

 
 

3. An electric motor in a fan uses an electromagnet

 
 

4. In the loudspeaker (or in speaker not mic) we use

 
 

5. The most preferable choice of material for the electromagnet is

 
 
 

6. Which of the following option will result in a stronger electromagnet

  1. turns in the coil are 50
  2. turns in the coil are 200
  3. turns in the coil are 500

If the rest of the parameters remain the same as voltage, current, etc.

 
 
 


 

8.0
Score

Pros

  • Difference between coil, solenoid and electromagnet
  • solenoid and helmholtz coil
  • Experiments that includes electromagnet

Cons

  • without physical picture