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Magnetism
Magnetism is simply an abstraction that people use for the changes in electromagnetic force created by the motion of electric charges. There are different types of magnetism that include electromagnetism, ferromagnetism, paramagnetism, and diamagnetism. To learn more and share your knowledge of magnetism and its types, ask and answer questions here.
4,020 Questions
What will attract steel but not brass?
A strong magnet will attract steel due to its ferromagnetic properties, while it will not attract brass as it is not a ferromagnetic material.
Why force exerted by a magnetic field on stationary elctric dipole is zero?
The force on a charge by a magnetic field is given by F = Bq v sin@
v - the speed of the charged particle with charge q. B - magnetic field induction in tesla. @ is the angle between the velocity vector and magnetic field vector.
As dipole is stationary, the speed of charges is zero. So the force = 0
Hence the result.
Why soft iron is used for making a permanent magnet?
Soft iron is not used for making permanent magnets; instead, it is used as a temporary magnet due to its high magnetic permeability and ability to be easily magnetized/demagnetized. Permanent magnets are typically made from hard magnetic materials like neodymium or ferrite, which can retain their magnetism for a long time.
What is the use of a magnet in a motor?
Magnets are used in motors to create motion. Magnets have two kinds of polarity, positive (north) and negative (south). When two magnets of the same polarity are facing each other, they will be attracted to each other. Conversely, if the polarity of the the two magnets are opposites than they two magnets will be repulsed. This concept of rotational motion is what is occurring in a motor.
How does the permanent magnet motor works?
In any electric motor, rotation is caused by two magnetic fields that oppose each other. In some motors, both fields are created by coils of wire - electromagnets. In other motors, one field is electromagnetic and the other comes from one or more permanent magnets. In the permanent magnet (PM) motor, the magnetic field from the permanent magnet(s) are constant (obviously) and the other field is turned on and off, or 'commutated' at just the right time so the fields oppose, causing rotation. Commutators can be mechanical - you have probably seen the brass segments around the rotor's end that the brushes touch - this is the commutator. In some motors, mostly small cooling fans and the like, commutation can be electronic using position sensors and switching transistors. These motors are called 'brushless'. Since the power of the motor comes from the opposing magnetic fields pushing on each other, the PM motor is only as powerful as the magnets used in its construction. There is quite a bit of research going on to create very powerful magnets for high performance PM motors used in radio controlled cars, planes and other applications where a powerful yet small motor is needed.
What happens when you put a magnet to a phone?
What part of the computer? what kind of monitor do you have?
if you stick the magnet to the screen it will appear to "kill" the colors. that's if you use an older model screen. I don't believe plasma screens will do the same thing with a magnet. the "melting" affect is like that if a pressing force on a plasma screen or a caculator screen. you can also ERASE your entire Harddrive with a powerfull enough magnet (or if it gets too close), be careful.
if you have already hurt your screen with the magnet, there is a degause button in the menu of your screens settings on the monitor. if your monitor is so old that you don't have a menu, get a new monitor.
A copper wire carrying current is most likely to be attracted to a magnet due to the magnetic field produced by the current flowing through it. Glass, a balloon, plastic piece, and chess piece are not typically attracted to magnets.
What is the procedure to draw magnetic field lines?
If it is a small magnet, like one that you can hold in your hand, place the magnet on a flat surface, put a white sheet of paper over it, take iron shavings or shavings from a magnetic metal, and sprinkle them on the paper. Gently shake the paper if you have to. You should start to see lines from where the magnetic fields attracted the metal.
Does a magnet contains a large number of magnetic domains or poles?
A magnet contains a large number of magnetic domains, not poles. Magnetic poles refer to the ends of a magnet where the magnetic field is strongest, while magnetic domains are regions within the magnet where the magnetic moments of atoms are aligned in a certain direction to contribute to the overall magnetic field of the magnet.
How can dropping a magnet destroy its magnetism?
There are molecules in a magnet that allow it to stick to other things. It has something to do with positive and negative charges or atoms in an atom cloud, but none of that is important unless you are a scientist. But dropping a magnet could scrape off those important molecules causing it to have less magnetism. It's not that big a difference, but should still be avoided.
A.A permanent magnet works because the individual magnetic fields of the molecules in the material are mostly aligned. It is the net effect of this magnetic alignment that we experience. Dropping a permanent magnet onto a hard surface sends vibrations rippling through the material, thus causing some of the molecules to change position and out of magnetic alignment. A magnet may have to be dropped or hit repeatedly to become completely demagnetized.A cone vibrates by oscillating back and forth in response to external forces or stimuli. The motion of the cone creates changes in air pressure, which produces sound waves that we can hear. The frequency and amplitude of the vibrations determine the pitch and volume of the sound produced.
What is the difference between horse shoe magnet and U-shaped magnet ped magnet?
A horseshoe magnet has two poles that are close together, which concentrate the magnetic field. A U-shaped magnet has a similar shape to a horseshoe magnet, but with one pole at each end, providing a more uniform magnetic field. A rod magnet has a simple cylindrical shape and its magnetic field is spread out along its length.
What will be attracted to or repelled by an magnet?
Materials that are attracted to a magnet are called ferromagnetic materials, such as iron, nickel, and cobalt. These materials have their own magnetic field that aligns with the external magnetic field. On the other hand, materials like wood, plastic, and glass are not attracted to magnets and are considered non-magnetic.
What happens when two opposite sides of a magnet are in contact with each other?
When two opposite sides of a magnet are in contact with each other, the magnetic fields align and attract each other, causing the magnet to stick together. This is due to the attraction between the opposite poles of the magnet.
Why does an electric current have a magnetic field?
A current carrying conductor, such as a metal wire, will produce a magnetic field around it because of the motion of charge within the wire itself. This motion produces or sets up a magnetic field around the wire in the form of concentric circles.
This electromagnetic effect is described in physics by the Biot-Savart Law, an experimentally deduced inverse-square law. The effect is also described by Ampère's Law, which is derived from the Biot-Savart Law. This law relates magnetic field and current.
Also, a magnetic field that is set up by an electrical current will produce a magnetic force. This force depends on the rate of charge transfer and the magnetic field.
The force produced by a current-carrying wire depends on the length, the magnetic field, and the current, which is the charge flow per unit of time.
What is a example of induced magnetism?
Magnetic fields can be generated by either a permanent magnet, or generating it by electrical flow such as through a coil.
If the magnet is then put near another material such as iron... the iron will then also start exhibiting an INDUCED magnetic field.
Induction motors operate on this principle with the armature being non-magnetic... and the motor operates by inducing a magnetic field into the armature.
Superconductors are unique that a magnet will induce an opposite magnetic field in them, and will be repulsed by the magnet.
Why does stroking a material with a magnet make it magnetised?
because the magnet causes particles called electrons in the atoms of the nail to align along the magnet's lines of force. The atoms with aligned electrons then act like tiny bar magnets themselves.
What if a magnetic needle is kept in a non uniform magnetic field?
A magnetic needle kept in uniform magnetic field will experience zero net force but non-zero net torque........Since the magnetic lines are uniform,the force acting on each end of the needlewill be equal and opposite.So it will cancel each other resulting zero net force.
What happen when you move two unlike magnetic poles closer together?
When two unlike magnetic poles are moved closer together, they will attract each other and the magnetic field lines between them will become stronger and more concentrated. This attraction will continue to increase as the poles move closer until they eventually come into contact.
How many magnetic poles do the pieces have when you break a magnet in half?
The best way to describe this would be to think of a magnet as a series of legos.
Imagine you have a stick of legos (those obnoxious 2 by 2 squares that can't be used for anything) stacked ten high.
No matter how many times, or where, you break the Lego stick, you still end up with one end having bumps and the other having a gaping hole.
The same is true for a magnet: at the smallest level, a magnet is a dipole, or a "particle", if you will, with one north side and one south side. Dipole stack on each other like legos in this metaphor we're using in such a way that, no matter where you break the magnet, you still have a dipole on the top pointing north and a dipole on the bottom pointing south.
Now, there is a hypothetical concept known as a "monopole" (think of a magnet that's ONLY north or ONLY south, like thinking of a Lego brick with ONLY bumps or ONLY holes), but we've never seen one, and physicists doubt they exist.
What causes magnets to attract to refrigerator?
Magnets are attracted to refrigerator doors because the doors are typically made of ferromagnetic materials like steel. The magnetic field of the magnet interacts with the atomic structure of the metal, causing the magnet to stick to the refrigerator.
How do water molecules act like '' little magnets''?
Water molecules act like little magnets because they are polar molecules, with a slightly positive charge on the hydrogen atoms and a slightly negative charge on the oxygen atom. This polarity allows water molecules to attract each other, forming hydrogen bonds which gives water its unique properties like surface tension and cohesion.
How many poles does a diamond-shaped magnet have?
A diamond-shaped magnet typically has four poles, one at each corner of the diamond shape. Two poles are opposite and attract each other, while the other two poles are also opposite and repel each other.
What labels north and south are the two ends of a magnet?
The end of a magnet that points towards the Earth's Geographic North Pole is labeled as the North Pole of the magnet, while the end that points towards the South Pole is labeled as the South Pole of the magnet.
What would happen if you put the north and the south poles of two magnets together?
If you put the north and south poles of two magnets together, they would attract each other and stick together. Conversely, if you put two like poles (north-north or south-south) together, they would repel each other and push away.
