SCIO HIGH SCHOOL Name: PHYSICS Period: CONTENT WORK- Presentation Date: February 5, 2018
Overview of Major Concept(s)
State and Explain Major Concept(s):: Iron is the most common element that is used in magnents because of its electrons. Electrons create magnetic fields by spinning. Most other elements are not as magnetic as iron due to their electrons canceling out eachothers magnetic field by spinning in opposite directions. Iron is so magnetic because four of its electrons spin the same way uncancled. Magnets always have a north seeking pole and a south seeking pole. Opposite poles attract, and like poles repel. Magnetic fields also behave with charged particles by deflecting them. this is why earth is not bombarded with cosmic radiation.
Historical Perspective: Magnetism was first discovered by William Gilbert, and was the first the investigate the mystery of magnetism using the scientific method. Gilbert was also the one to discover that the Earth itself was a very weak magnet. Since then, magnetism has been studied by many other scientists. Most noteably, Carl Friedrich Gauss, Charles Coulomb, and Hans Christian Oersted.
Application of Concept(s): Magnetism was first discovered by William Gilbert, and was the first the investigate the mystery of magnetism using the scientific method. Gilbert was also the one to discover that the Earth itself was a very weak magnet. Since then, magnetism has been studied by many other scientists. Most noteably, Carl Friedrich Gauss, Charles Coulomb, and Hans Christian Oersted.
Think and Explain Questions
Answers: 1. A stationary electric charge is surrounded by a magnetic field, and an electric field surrounds a charge in motion. 2. Iron has an odd amount of free electrons, makings it ferromagnetic. Wood is not ferromagnetic. 3. The iron fillings act as an outline that shows the magnetic fields because they are magnetic. However, they are not magnets. 4. The magnets exert the same amount of force on one another. 5. The magnetic domains in the iron are induced into allignment. Because this further increases the magnetic field intensity, it becomes an electromagnet.
6. The plasma must be moving in order to keep it from escaping. 7. A magnetic field holds the particles in a circular motion, while the electric field increases the speed it is traveling. 8. It cannot do work on them because it is the tangential component to the electromagnetic force. 9. The force on the particles is greatest when it is moving perpendicular to the magnet, and the force is less, or zero when the particle is moving parallel with the field. 10. It allows the pigeons to determine their latitude, longitude, and altitude. 11. The intensity of the cosmic rays was greater when Earth was in the zero phase.
Review Questions
Answers: 1. Both of them have poles. Opposites attract and like poles repel. 2. Magnetic poles cannot be isolated whereas electric charges can. 3. The source of a magnetic field is a magnet. A magnetic field is the space around a magnet, in which the magnetic force is exerted. 4. Not every atom is a magnet because most atoms have electrons spinning in the opposite directions to cancel out the magnetic force. Some atoms only have one electron that is not counteracted whereas iron has 4. 5. Iron has 4 electrons that spin in the same direction that are uncanceled. This is why Iron has the greatest magnetic properties. 6. A magnetic domain is a cluster of aligned iron atoms. 7. The pieces of iron that do not behave as magnets are not aligned, whereas iron that does behave as a magnet is aligned. 8. A piece of iron can be induced into becoming a magnet by rubbing a manet against it. This in turn will alaign the iron atoms causing a magnetic domain. The paper clip near the magnet will also become a magnet but a very weak one. 9. This will weaken a magnet because it will make the domains split up by changing the alignment of the atoms. 10. A concentric circle. 11. It is stronger because the current overlaps on the inside causing a greater force. 12. It has to move in the magnetic field. 13. The direction of the magnetic force is perpendicular to the motion of the charge. 14. It deflects cosmic radiation. 15. They both are forced perpendicular to the magnetic field lines. 16. When an electrical current passes through the loops of insulated wire they have a force on the needle from the magnetic fields produced. 17. This allows the motor to keep going.
18. It means that a compass doesn't point to true north, but to the magnetic north pole. 19. Convection currents, molten parts of earth's core, and moving charges within the earth. 20. Magnetic pole reversals occur when the magnetic poles reverse. Scientists can determine this by investigating the strata with insturments to determine the magnetic state of the strata at that time.