Magnetic field and electric field are correlated and integral parts of the electromagnetic force. They are also one of the four primary forces present in nature. Do you know what a magnetic field is, and can you block a magnetic field? In this article, we will also learn about magnetic shielding and find out whether it is possible to stop a magnetic field. There are other interesting questions, like can we reduce the magnetic field in our room and what is the best shielding ability, to which you will get the answers in this article. So read on to find out.
1. How do You Shield a Magnet?
There is no way to shield or block a magnetic field. We can only redirect the magnetic fields. Ferromagnetic substances (material that attracts magnets) like iron, cobalt, steel, and nickel can redirect and attract the magnetic fields towards themselves. However, it also depends on the material’s density on how strongly and quickly it can redirect or attract the magnetic field. (See What is the best piece of evidence for plate tectonics?)
2. Can You Block a Magnetic Field?
No, we cannot shield or block a magnetic field. The fields can only be redirected to another material like iron, cobalt, nickel, or steel. Let’s understand the redirection of the magnetic fields in detail. Suppose there is a huge area that has a static magnetic field, and we want to alter the area’s magnetic field strength rapidly. So, is it possible to curve the field and redirect the nearby fields towards one single point and increase the flux strength and density? Let’s find out its answer.
Yes, using a shaped magnetic element, it is possible to redirect magnetic field lines. A cone-shaped piece of iron, for instance, can be used to collect an external magnetic field, just as field lines do when entering the south pole of a magnet from a wide area. The cone can be positioned so that a large static field enters the wide end of the cone. The iron limits the field and guides it to the top of the cone, where it rises with a considerably higher density and, hence, we get a much stronger magnetic field.
3. How do You Stop a Magnetic Field?
The clear answer to this whether can you block a magnetic field or stop it is no. The magnetic field cannot be completely blocked.
If you want the magnetic fields to block naturally, then the only way is for the magnetic field lines to end on the opposite pole. Otherwise, it cannot be stopped. Our planet’s magnetic fields are the best example here.
If you want to remove the effect of magnetic fields from a particular device, then re-routing or redirecting the magnetic field can be used to protect the equipment or device from magnetic fields. This process, also known as magnetized shielding, involves enclosing the equipment that has to be protected inside a building built of or containing material with extremely high magnetic permeability, such as steel. The magnetic field then moves through that material, diverting its lines of force away from vulnerable electronic components and other parts that need to be protected. (See What are Magnetic Substances?)
4. How can You Reduce the Magnetic Field in Your House?
Can you block a magnetic field? No, but there are several ways to reduce the magnetic field in your house. Some of them have been listed below:
- Electric appliances produce electrical fields, so to reduce their effect, try switching them off when they are not in use. Try to stay away from electrical appliances that produce high magnetic fields. Remember that you can reduce the effects of a magnetic field but not stop it.
- You can also talk to companies that measure electrical or magnetic fields. They can also give you tips on how to reduce the magnetic field effects in your house.
- You can buy a magnetometer (PCE-MFM 3000), which detects the magnetic fields in your house. If you know the range of magnetic fields, then you can take action to reduce them if the detection range is on the high side. Otherwise, it is not required.
Moreover, due to the massive electric currents carried by the lines and the difficulty in shielding magnetic fields, homes close to large power lines frequently have magnetic fields that are higher than the average. However, electric fields generated by power lines do not reach indoors because buildings efficiently filter electric fields.
5. What Materials Block Magnetic Fields?
Can you block a magnetic field? No, it is not possible to block the magnetic fields, but yes, the magnetic fields can be redirected with the help of ferromagnetic materials, which get attracted magnets. These types of materials or substances are iron, steel, nickel, and cobalt.
Our magnetic shields are created from ferromagnetic metal alloys, which are magnetic-permeable metal alloys (such as iron, nickel, or cobalt). These substances have the ability to attract the magnetic field and focus the flux lines along their surfaces. The permeability of the selected material has the biggest impact on the weakening (attenuation) of the magnetic shield. The attenuation will increase with the rise in permeability. Also, higher permeability means higher attenuation.
Moreover, ferromagnetic materials’ permeability varies nonlinearly with H’s magnetic induction. In other words, some materials will be more suitable for magnetic fields with low magnetization than others, and vice versa.
Note: Magnetic permeability is the magnetic induction’s ratio to magnetic intensity. It measures a substance’s resistance to the magnetic field. Check out Magnetic Compass is used to Find What?
6. Which Metal has the Best Shielding Ability?
Metals that have the best shielding ability are the following:
- Carbon steel
- Copper (copper alloy 770)
- Nickel silver
- Pre-tin plated steel
Electromagnetic interference (EMI) is required for designing almost every device available in the market, such as a medical apparatus, a GPS navigation system, or any microprocessor. And the above-mentioned metals are best for shielding against EMI.
Due to its exceptional ability to attenuate magnetic and electrical waves, copper is the most trustworthy metal for EMI shielding. Copper’s application in RFI shielding serves the purpose well for everything from hospital MRI machines to basic computer hardware. This metal, along with its alloys, brass, phosphorous bronze, and beryllium copper, is very versatile and simple to fabricate.
7. Will a Magnet go through Aluminum?
Aluminum is not magnetic under normal conditions, mostly due to the crystal structure of the metal. Along with metals like magnesium and lithium, it is referred to as a paramagnetic substance. (See What are the uses of electromagnets in daily life?)
8. Does Aluminum Foil Block a Magnetic Field?
The majority of high-frequency shielding issues aren’t brought on by the material itself but rather by gaps in the shield. The majority of conductive materials, including mild steel, copper, and aluminum, offer significant electric shielding. Aluminum foil has a shielding efficiency of at least 85 dB at frequencies between 30 and 100 MHz.
However, thick steel or highly permeable ferrite material provides more appropriate shielding than aluminum foil does against low-frequency magnetic fields. These circumstances are just a few of the many factors that reduce shielding’s efficiency and necessitate additional filtering.
9. Can Copper Block Magnetic Fields?
Can you block a magnetic field? As a material, copper is not magnetic. However, when a magnet comes close to copper (and some other metals), the magnetic field causes the copper’s surface electrons to reorganize, and it starts to revolve. They generate resistance when they move in a circular motion perpendicular to the magnetic field.
10. What can Block Electromagnetic Waves?
Can you block a magnetic field and electromagnetic waves? We can use materials like copper, nickel, zinc, brass, and carbon steel to reduce the effect or redirect the electromagnetic waves. (See Where the Earth receives energy from?)