Many dried cereals are fortified with iron, i m sorry is included to the cereal in the type of small iron particles. How could these corpuscle be separated indigenous the cereal?
Magnetic fields are caused by electrical charges in motion.Even for "permanent magnets" wherein no electric present is obvious, the field is tho created because electrons are in motion: orbiting the nucleus, or "spinning" around their own axes. Thus, we might say the all magnets space electromagnets.

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Magnetic field is a vector quantity. Though every atoms contain moving charges, in part atoms the result magnetic areas cancel every other, and also the product is nonmagnetic.
To do a compass, suggest an ordinary iron pond along the direction the Earth"s magnetic field (which in the northern Hemisphere, is angled downward and northward) and repeatedly strike it because that a few seconds v a hammer or a rock. Then suspend it at its facility of gravity by a string. Why does the act of highlight magnetize the nail?
You make a bar magnet through jiggling the magnetic domains and also letting castle align with the Earth"s field.
If you location a chunk the iron close to the phibìc pole the a magnet, attraction will occur. Why will attraction likewise occur if you place the very same iron near the southern pole of the magnet?
The north pole that the bar magnet induces south poles top top the closer next of a piece of iron. In the same way, the southern pole induces phibìc poles in the iron. This reasons the attraction.
Do the poles the a horseshoe magnet lure each other? If you bending the magnet so the the poles acquire closer together, what happens to the force between the poles?
Yes. The force will increase. The opposite magnetic poles lure each other. Once opposite poles acquire closer, the attractive pressure is greater.
Opposite magnetic poles attract each other.If the magnet is too flexible, it will certainly bend, possibly enabling the poles come touch, and weakening the adjacent external magnetic field.
What sort of force field surrounds a stationary electric charge? What extr field surrounds it once it moves?
Any electrical charge establishes an electrical field approximately itself.If the is moving, a magnetic field also appears.Since the charge has mass, over there is also a gravitational field.
What is different about the magnetic poles of common refrigerator magnets and also those of usual bar magnets?
Refrigerator magnets room made with alternate stripes of north and also south poles. Castle are reasonably weak due to the fact that the differing-direction magnetic areas caused by the stripes cancel out as soon as you are only a brief distance away.
A friend tells you that refrigerator door, in ~ its class of painted plastic, is do of aluminum. How might you inspect to check out if this is true (without any scraping)?
Try trial and error the door through a magnet. Aluminum is not magnetic, so if the sticks, s/he is mistaken.However, if that doesn"t stick, the doesn"t prove that the door is made of aluminum, due to the fact that there are plenty of nonmagnetic materials.
The phibìc pole that the bar magnet induces southern poles top top the closer side of the nail or paper clip. In the exact same way, the south pole induces north poles in the nail or document clip. This causes the attraction.However, a wood pencil go not have actually magnetic domains that would certainly be impacted by the long-term magnet.
Will one of two people pole of a magnet lure a file clip? define what is happening within the attracted paper clip.
Yes. The phibìc pole the the bar magnet lines up magnetic domain names in the document clip, in together a fashion the the domain"s southern pole are on the closer side. In the very same way, the south pole induces phibìc poles in the record clip.This reasons the attraction.
One way to make a compass is come stick a magnetized needle right into a piece of cork and also float that in a glass bowl complete of water. The needle will certainly align itself with the horizontal component of Earth"s magnetic field. Since the north pole that this compass is attractive northward, will the needle float toward the north next of the bowl? safeguard your answer.
No. Over the diameter that the bowl, the Earth" magnetic ar may be considered to be constant. Despite the phibìc pole that the needle is attractive northward, the entire needle doesn"t float northward since the other finish is attractive southward. The net pressure on the needle is zero.
There room two factors involved. First, the iron filings turns into tiny magnets due to the fact that their domains align in the field. Second, if the submit is no parallel to the exterior magnetic field lines, a net torque acts on it and rotates it until it aligns follow me the ar lines, as with a small compass needle.
The north pole of a compass is attracted to the north magnetic pole the Earth, yet like poles repel. What go this indicate around the polarity that Magnet earth at the poles.
The planet must have a magnetic southern pole situated in the northern Hemisphere, and a magnetic phibìc pole situated in the southerly Hemisphere.
We know that a compass point out northward because Earth is a gigantic magnet. Will certainly the northward-pointing needle suggest northward when the compass is brought to the southern hemisphere?
Yes. The compass lines up with the Earth"s magnetic field. This ar points from the north magnetic pole located in the southerly Hemisphere come the southern magnetic pole located in the north Hemisphere.
In what position have the right to a current-carrying loop of cable be located in a magnetic field so the it doesn"t have tendency to rotate?
The axis that the current-carrying loop that wire need to be inside wall up or parallel through the magnetic field.
Magnet A has twice the magnetic field strength that magnet B (at same distance) and, in ~ a specific distance, it traction on magnet B with a pressure of 50 N. With how much force, then, go magnet B traction on magnet A?
50 N. Newton"s 3rd law. Whenever object A exerts a force on thing B, we discover that thing B exerts an equal and opposite force on thing A.
When a magnet exerts pressure on a current-carrying wire. Walk the current-carrying wire exert a pressure on a magnet?
Yes.Newton"s third law. Whenever thing A exerts a force on thing B, we discover that thing B exerts one equal and also opposite pressure on thing A.
A strong magnet attractive a file clip to itself with a particular force. Does the document clip exert a pressure on the strong magnet? If not, why not? If so, does it exert together much force on the magnet as the magnet exerts top top it? safeguard your answers.
Yes, that exerts a pressure of same magnitude.Newton"s 3rd law. If the magnet exerts a force on the record clip, we discover that the record clip exerts one equal and opposite force on the magnet.
A right current-carrying wire is horizontal and also oriented south to north. When a compass needle is placed below or over it, in what direction go the compass needle point?
A loudspeaker consists of a cone attached to a current-carrying coil situated in a magnetic field. What is the relationship in between vibrations in the current and also vibrations of the cone?
The vibrations occur at the same frequency.When the existing in the coil increases, it becomes a stronger electromagnet, and also feels a stronger force from the irreversible magnet. Once the existing decreases, the coil feels less force.Thus, the mechanically vibrations that the speaker happen in action with the variations in the current.
Will a superconducting magnet use less electric power 보다 a classic copper-wire electromagnet of the same field strength? defend your answer.
It will use less power.There is no electrical resistance in the superconducting magnet, so over there is no heat loss. It will certainly take less power (in fact, no power) to store the existing moving, do it more efficient 보다 a traditional copper-wire electromagnet.
When iron-hulled marine ships room built, the location of the shipyard and the orientation of the ship in the shipyard are videotaped on a brass plaque permanently attached to the ship. Why?
When the delivery is manufactured, the stole hull is heated and also struck during the an extensive manufacturing process. The heating and the impacts permit the magnetic domains in the hull to align with the Earth"s magnetic field, and also the hull i do not care magnetized. The hull"s magnetic ar strength and also orientation may be of attention for historians, or for later on magnetic measurements, and also so the is videotaped on a plaque.
A beam of electrons passes v a magnetic field without being deflected. What can you conclude about the orientation of the beam family member to the magnetic field?
The electron beam is traveling parallel (or anti-parallel) come the magnetic field.The magnetic pressure on the moving charges is zero as soon as it move parallel come the magnetic field lines.
Can an electron at remainder in a stationary magnetic field be collection into motion by the magnetic field? What around the electron inserted at remainder in an electrical field?
No and yes, respectively.A magnetic ar exerts no force on a stationary charge. In an electric field E, a fee q feels a force of magnitude q×E. A stationary electron will certainly be set into motion.
A proton move in a circular path perpendicular come a consistent magnetic field. If the ar strength the the magnet is increased, walk the diameter the the circular route increase, decrease, or continue to be the same?
The diameter decreases.When the ar is strengthened, the proton is pulled into a tighter, smaller-diameter circular path. If the field were weakened, the proton would certainly feel much less force, and also move in a straighter, larger-diameter path.
Two charged particles are projected into a magnetic field that is perpendicular to their velocities. If the particles room deflected in the contrary directions, what does this phone call you around them?
The charges space of the opposite sign.Oppositely fee particles feel pressures in opposite direction in an electrical field. The very same is true of identically-directed particles in magnetic fields. If these particles room deflected in opposite direction (say, one to the east, and one come the west), the charges must be of the opposite sign.
A magnetic ar can direction a beam the electrons, yet it can not do job-related on the electron to change their speed. Why?
The magnetic force that acts on a charged fragment is always perpendicular come the particle"s motion.There is no ingredient of the pressure that acts follow me the instantaneous direction the motion, so the ar cannot rate up, or slow down, a relocating charged particle.
Inside a activities room there is said to be one of two people an electric field or a magnetic field, but not both. What experiments could be performed to establish what type of field is in the room?
First, one could put a bar magnet in the room and also see what happens. Does the align with a magnetic field?Second, one might put a stationary electrical charge in the room. A magnetic field exerts no pressure on a stationary charge. However, in an electric field E, a fee q feeling a pressure of size q×E. A stationary charge will be collection into motion.
Residents of north Canada room bombarded by more intense cosmic radiation than occupants of Mexico. Why is this so?
Charged particles relocating in a magnetic ar are deflected the many when they move at appropriate angles to the ar lines, and also deflected the least when they move parallel come the field lines. Cosmic rays (high-energy charged particles) that are heading towards regions close to the Earth"s poles (such as north Canada) room moving an ext parallel to the Earth"s magnetic ar lines, and are deflected less. For areas closer come the equator (such as Mexico), incoming cosmic rays move more nearly at right angles to the Earth"s magnetic field, and also are deflected away.
Cosmic beam that are deflected through Earth"s magnetic fields can it is in trapped in the valve Allen radiation belts. These high-energy charged particles space unhealthy for astronauts.
What transforms in cosmic-ray intensity in ~ Earth"s surface ar would you expect throughout periods in i beg your pardon Earth"s magnetic field passed v a zero phase while experience pole reversals?
Cosmic beam intensity in ~ the Earth"s surface is greater.Incoming cosmic rays move at an angle to the Earth"s magnetic field, and are deflected away.When the Earth"s magnetic field passes v a zero phase, this defense diminishes, and an ext cosmic rays with the surface.
In a fixed spectrometer, ions room directed into a magnetic field, whereby they curve and strike a detector. If a variety of singly ionized atoms travel at the very same speed with the magnetic field, would certainly you suppose them every to it is in deflected by the exact same amount, or would various ions it is in bent different amounts? safeguard your answer.
They would certainly be bend by various amounts.The singly-charged ions have the same charge and also the very same speed in the same direction, and experience the very same magnetic force. However, the amount lock bend counts on their accelerations, which depends on your masses.The lighter ions will be deflected an ext than the more heavier ones.
One means to shield a habitat in outer an are from cosmic light ray is v an absorbing blanket of part kind, which would function much like the atmosphere that protects Earth. Speculate ~ above a second means for shielding the habitat the would additionally be comparable to Earth"s herbal shielding.
If a magnetic field were established approximately the habitat, it could shield astronauts native cosmic light ray by the same principle by which the magnetic ar of the planet shields the surface.
If you had actually two bars of iron, one magnetized and one unmagnetized, and also no other materials at hand, how might you recognize which bar to be the magnet?
Place the end of one bar at the midpoint the the other.The magnetic field of a bar magnet is strongest at the ends ar the end of bar A in ~ the midpoint that bar B (making the letter "T"). If over there is a relatively strong attraction, bar A is the magnet, and also if not, bar B is the magnet.
Historically, instead of dirt roads with paved roads reduced friction top top vehicles. Replacing led roads with steel rails reduced friction further. What recent step eliminates rail friction that vehicles? What friction stays after rail friction is eliminated?
The method of magnetic levitation eliminates rail friction, due to the fact that the train doesn"t also touch the rail.Drag pressures (forces as result of friction through air) remain.
Yes.Each current-carrying cable creates a magnetic field around it. Each present experiences a force because it is in the magnetic ar generated through the various other current-carrying wire.
what is the magnetic result of placing 2 wires with equal yet oppositely command currents close with each other or twisted about each other?
The magnetic fields developed by the 2 wires will nearly cancel.When you turning back the direction the a current, the direction the the magnetic field it create will additionally reverse.

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In preparation for one MRI scan, why room patients advised to eliminate eyeglasses, watches, jewelry, and other steel objects?
The MRI machine uses a large magnet, and also those objects could contain iron and also be attracted to the machine.



Engineering Electromagnetics (Irwin electronic devices & computer Enginering)8th EditionJohn Buck, william Hayt