Magnetism Review

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Magnetism Review. For magnets, like poles repel each other and unlike poles. also repel each other. attract each other. can disappear into nothingness. can carry a lot of energy. For magnets, like poles repel each other and unlike poles. also repel each other. attract each other. - PowerPoint PPT Presentation

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Chapter 10

MagnetismReviewFor magnets, like poles repel each other and unlike polesalso repel each other.attract each other.can disappear into nothingness.can carry a lot of energy.

2Answer: BFor magnets, like poles repel each other and unlike polesalso repel each other.attract each other.can disappear into nothingness.can carry a lot of energy.3Answer: BThe source of all magnetism istiny bits of iron.tiny domains of aligned atoms.the motion of electrons.small lodestones.

4Answer: CThe source of all magnetism istiny bits of iron.tiny domains of aligned atoms.the motion of electrons.small lodestones.Comment: This is true for electrons moving in a beam or electrons spinning or orbiting the nuclei of atoms such as iron.5Answer: CA strong magnet lifts a paper clip. Compared with the force the magnet exerts on the clip, the force the clip exerts on the magnet ismuch less.slightly less.the same.slightly more.

6Answer: CA strong magnet lifts a paper clip. Compared with the force the magnet exerts on the clip, the force the clip exerts on the magnet ismuch less.slightly less.the same.slightly more. Explanation: This is Newtons third law. In the interaction between the paper clip and the magnet, both forces are equal and opposite.7Answer: CMagnet A has twice the field strength of Magnet B. When brought close together, the magnet that pulls harder on the other isMagnet A.Magnet B.Both forces are equally strong.dependent on their distances apart.

8Answer: CMagnet A has twice the field strength of Magnet B. When brought close together, the magnet that pulls harder on the other isMagnet A.Magnet B.Both forces are equally strong.dependent on their distances apart.Explanation: This is Newtons third lawthe force that A exerts on B is equal and opposite to the force that B exerts on A.9Answer: CSurrounding moving electric charges areelectric fields.magnetic fields.Both of these.None of these.

10Answer: CSurrounding moving electric charges areelectric fields.magnetic fields.Both of these.None of these.Comment: Dont forget that electric fields surround electric charges!11Answer: CThe magnetic domains in a magnet produce a weaker magnet when the magnet isheated.dropped on a hard surface.Either of these.None of these.

12Answer: CThe magnetic domains in a magnet produce a weaker magnet when the magnet isheated.dropped on a hard surface.Either of these.None of these.13Answer: CMagnetic domains occur mainly for materials composed ofcarbon.copper.silver.iron.

14Answer: DMagnetic domains occur mainly for materials composed ofcarbon.copper.silver.iron.15Answer: DA bar magnet that holds a chain of paper clips illustratesmagnetic field displacement.magnetic induction.electromagnetic induction.Faradays law.

16Answer: BA bar magnet that holds a chain of paper clips illustratesmagnetic field displacement.magnetic induction.electromagnetic induction.Faradays law.17Answer: BWhen a bar magnet is broken in half, the magnetic strength of each piece isless than half.about half.the same.somewhat increased.

18Answer: CWhen a bar magnet is broken in half, the magnetic strength of each piece isless than half.about half.the same.somewhat increased.

19Answer: CThe magnetic field lines about a current-carrying wire formcircles.radial lines.eddy currents.spirals.

20Answer: AThe magnetic field lines about a current-carrying wire formcircles.radial lines.eddy currents.spirals.21Answer: AA magnetic force cannot act on an electron when itis at rest.moves parallel to magnetic field lines.Both of these.None of these.

22Answer: CA magnetic force cannot act on an electron when itis at rest.moves parallel to magnetic field lines.Both of these.None of these.Explanation: A force is exerted on charged particles only when they move at an angle to magnetic field lines. The force is greatest when motion is at right angles to the magnetic field.23Answer: CA magnetic force acts most strongly on a current-carrying wire when itcarries a very large current.is perpendicular to the magnetic field.Either or both of these.None of the above.

24Answer: CA magnetic force acts most strongly on a current-carrying wire when itcarries a very large current.is perpendicular to the magnetic field.Either or both of these.None of the above.25Answer: CThe magnetic field surrounding Earth helps shield us from cosmic rays.is likely caused by electric currents in its interior.changes over time.All of these.

26Answer: DThe magnetic field surrounding Earth helps shield us from cosmic rays.is likely caused by electric currents in its interior.changes over time.All of these.27Answer: DMagnetic materials are found in the bodies ofbees.birds.bacteria.All of these.

28Answer: DMagnetic materials are found in the bodies ofbees.birds.bacteria.All of these.29Answer: D