Permanent Magnets and Electromagnets - GeeksforGeeks (2023)

Magnetic field and strength are the main differences between permanent magnets and electromagnets. A coil of wound wire creates the magnetic field in an electromagnet, while the magnetic field of a permanent magnet (bar magnet) cannot be changed. The strength of a permanent magnet is determined by the material used in its construction, but the strength of an electromagnet is determined by the passage of electric current through it. Ceramic magnets, flexible magnets, neodymium iron boron magnets, and samarium cobalt magnets are the four types of permanent magnets (bar magnets). Each has its own uses and types.

Let's take a closer look at the differences between a permanent magnet and an electromagnet.

Dauermagnet

These magnets have the ability to retain their magnetism and magnetic properties for a long period of time. Permanent magnets are made ofstrong magnetic hartstoffe. The bar magnet is an excellent example of a permanent magnet. This magnet shows the behavior of magnets in great detail. Permanent magnets are also known asstabbing magnet.

Types of permanent magnets

This section discusses the many types of permanent magnets. They are the following:

1. Ceramic magnets:They are the least expensive permanent magnets available. We use them in the food processing industry, as well as in magnetic resonance imaging and other areas.
2. Magneto Flexible: They are used in the seals of the doors of the refrigerators. Rubber polymers, plastics, and magnetic powders can all be used to make them.
3. NdFeB (Neodymium iron boron magnet):These are rare earth magnets. It is quite easy to rust. It is a high-priced substance. It is commonly used in jewelry making, bookbinding, and other crafts.
4. Cobalt samarium magnet (SmCo):These are also rare earth magnets. It is resistant to temperature and oxidation. They have a stronger magnetic field. They can be used in high end engines, turbomachinery and other applications.

Application of permanent magnets

• Hard drives, motors, vehicles, generators, televisions, telephones, headphones, speakers, transducers, and sensors all require permanent magnets. The most common purpose of a magnet is to attract other magnetic things, but it also serves a variety of purposes in electrical devices.
• Most speakers use a permanent magnet that interacts with a coil of wire (actually an electromagnet). The audio signal travels along the cable, causing the speaker to move. The speaker creates sounds by moving air.
• Magnetic hooks or snaps are often found on cabinets or other furniture doors. They are usually made with a cheap ceramic magnet sandwiched between two steel plates that attract and touch a steel "lock plate" on the door.

Disadvantages of permanent magnets

• The magnetic field of a permanent magnet can only be generated below a certain temperature. Therefore these magnets are not suitable for use in hot device applications.
• Over time, these permanent magnets deteriorate. This reduces the intensity of the maximum magnetic field. The poles of the permanent magnet cannot be changed.

Electromagnet

The device acts like a magnet when a battery is connected to a solenoid (a coil of wire wrapped around a nail). The magnetic field created by the current flowing through the coil is responsible for this. The magnetism of the nail lasts as long as it passes through the coil; If no current flows, the magnetism of the nail is lost. If youWrap a coil of wire around an iron core., you can do itElectromagnet.

See Also

difference between permanent magnet and electromagnet | Linquip

types of electromagnets

Electromagnets are classified as resistive, superconducting, or hybrid magnets.

1. Heavy Duty Electromagnets:This type of magnet uses copper wires to create a magnetic field. The magnetic field is created when a copper wire is wrapped around a piece of iron and an electric current is passed through the copper wire. The stronger the field, the more copper wires are twisted.
2. Hybrid Electromagnets:They are a hybrid of the two types of electromagnets mentioned above, resistive and superconducting electromagnets.
3. Supraleotroiman:They are made of superconducting metal that offers no resistance to the flow of electricity. The same approach is used to make superconducting magnets. With these electromagnets, the temperature of the copper coil is lowered with liquid nitrogen or liquid helium. The low temperature separates the copper atoms from the current flow, creating a high magnetic field. Even when the power is turned off, these electromagnets continue to work.

Application of electromagnets

• Electromagnets are the most common type of magnet used in transformers. When you power the transformer, the coils create alternating magnetic fields. This creates tension. Transformers are commonly used in electric power systems to manage alternative voltages.
• You can get the voltage you want whenever you want. We can achieve this by changing the current flow. Electromagnets can also be used in magnetic locks, relays, maglev trains, electric bells, and speakers, among others.

Disadvantages of electromagnets

• Copper compounds are required in a variety of electromagnets. Therefore, they are not suitable for use in compact areas. They also need a lot of care. The electromagnet can be damaged by the short circuit.
• Electromagnets require a constant current source. Due to numerous variables, such as resistive heating, inductive transients, core losses, coil coupling, etc., this may affect the magnets and their field at some point in the future.

Difference Between Permanent Magnet and Electromagnet

The difference between a permanent magnet and an electromagnet is as follows:

• Permanent magnets are permanently magnetized while electromagnets are temporarily magnetized.
• The former is made of hard materials while the latter is made of soft materials.
• With permanent magnets, the strength of the magnetic field lines is fixed, that is, it cannot be changed, while with electromagnets, the strength of the magnetic field lines can be adjusted to our needs.
• In the first, the poles are fixed, in the second, the poles can vary.

Similarities Between Permanent Magnets and Electromagnets

Both magnets have fictitious magnetic field lines. Magnets have north and south poles, and their behavior is determined by Earth's geographic north and south poles. The properties of magnetism are present in both magnets.

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sample questions

Question 1: Why is soft iron used as an electromagnet?

Answers:

When current flows, the soft iron in the coil becomes a magnet, increasing the magnetic field. Since soft iron loses its magnetic power once current stops flowing, it's a good choice.

Question 2: Why do manufacturers use steel to make permanent magnets?

Answers:

Steel is an alloy of iron and carbon. Steel is not magnetic in its original form, but it can be transformed to become magnetic. When a non-magnetic piece of steel is brought close to a magnet, the atoms it contains rearrange to form a permanent magnet. When the atoms align, a magnetic field is created that maintains its strength. The atoms of an object must be correctly aligned to create a magnetic field. Due to the inherent arrangement of its atoms, steel is extremely useful for this purpose.

Question 3: What is the difference between a permanent magnet and an electromagnet?

Answers:

A permanent magnet is a material object that becomes magnetized and creates its own magnetic field. On the other hand, if an electric current is allowed to flow through a coil of wire, it acts like a magnet called an electromagnet.

Question 4: What are the advantages of an electromagnet over a permanent magnet?

Answers:

The main advantage of electromagnets is that they can control their magnetic attraction by turning the magnet on or off and changing the current. They also have a stronger attraction than permanent magnets. By some estimates, the largest electromagnet is 20 times stronger than the strongest permanent magnet.

Question 5: What is a magnet used for?

Answers:

Electric generators use magnets to generate electricity while electric motors use magnets to convert electrical energy into mechanical energy. It is used by speakers, electric doorbells, maglev trains, television and computer screens, cell phones, refrigerators, and other electronic devices.

Question 6: What are the advantages of electromagnets over permanent magnets?

Answers:

Permanent magnets are more expensive. Electromagnets are cheaper. This is due to the lower cost of the materials used in the electromagnet. The magnetic strength of an electromagnet can be adjusted to suit your needs. This is not feasible with a permanent magnet.