Chapter 8 Review
Key Terms
cosmic rays
comprised of particles that originate mainly from outside the solar system and reach Earth
cyclotron
device used to accelerate charged particles to large kinetic energies
dees
large metal containers used in cyclotrons that serve contain a stream of charged particles as their speed is increased
gauss
unit of the magnetic field strength;
Hall effect
creation of voltage across a current-carrying conductor by a magnetic field
helical motion
superposition of circular motion with a straight-line motion that is followed by a charged particle moving in a region of magnetic field at an angle to the field
magnetic dipole
closed-current loop
magnetic dipole moment
term of the magnetic dipole, also called
magnetic field lines
continuous curves that show the direction of a magnetic field; these lines point in the same direction as a compass points, toward the magnetic south pole of a bar magnet
magnetic force
force applied to a charged particle moving through a magnetic field
mass spectrometer
device that separates ions according to their charge-to-mass ratios
motor (dc)
loop of wire in a magnetic field; when current is passed through the loops, the magnetic field exerts torque on the loops, which rotates a shaft; electrical energy is converted into mechanical work in the process
north magnetic pole
currently where a compass points to north, near the geographic North Pole; this is the effective south pole of a bar magnet but has flipped between the effective north and south poles of a bar magnet multiple times over the age of Earth
right-hand rule-1
using your right hand to determine the direction of either the magnetic force, velocity of a charged particle, or magnetic field
south magnetic pole
currently where a compass points to the south, near the geographic South Pole; this is the effective north pole of a bar magnet but has flipped just like the north magnetic pole
tesla
SI unit for magnetic field:
velocity selector
apparatus where the crossed electric and magnetic fields produce equal and opposite forces on a charged particle moving with a specific velocity; this particle moves through the velocity selector not affected by either field while particles moving with different velocities are deflected by the apparatus
Key Equations
| Force on a charge in a magnetic field | |
| Magnitude of magnetic force | |
| Radius of a particle’s path in a magnetic field | |
| Period of a particle’s motion in a magnetic field | |
| Force on a current-carrying wire in a uniform magnetic field | |
| Magnetic dipole moment | |
| Torque on a current loop | |
| Energy of a magnetic dipole | |
| Drift velocity in crossed electric and magnetic fields | |
| Hall potential | |
| Hall potential in terms of drift velocity | |
| Charge-to-mass ratio in a mass spectrometer | |
| Maximum speed of a particle in a cyclotron |
Summary
8.1 Magnetism and Its Historical Discoveries
- Magnets have two types of magnetic poles, called the north magnetic p