Electromagnetic Force - Model of the atom proposed by
Neils Bohr in 1913. It showed electrons in fixed orbits around
the nucleus, but acting in some ways like waves.
- Radiation that travels through
vacuous space at the speed of light and propagates by the
interplay of oscillating electric and magnetic fields. This
radiation has a wavelength and a frequency.
Electromagnetic Spectrum - The entire range of all the
various kinds or wavelengths of electromagnetic radiation,
including (from short to long wavelengths) gamma rays, x-rays,
ultraviolet, optical (visible), infrared, and radio waves.
Electron - A negatively charged elementary
particle that normally resides outside (but is bound to) the
nucleus of an atom.
Electron Cloud Model - Scientific machine in which
particles are accelerated as they travel around a circular path.
Electron Flux - The rate of flow of electrons
through a reference surface. In cgs units, measured in electrons
s-1, or simply s-1.
Electron Volt - Abbreviated eV. A unit of energy
used to describe the total energy carried by a particle or
photon. The energy acquired by an electron when it accelerates
through a potential difference of 1 volt in a vacuum. 1 eV = 1.6
x 10-12 erg.
Electron Volt (eV) - Attraction or repulsion due to
the electric charge of matter.
Energy Flux - The rate of flow of energy
through a reference surface. In cgs units, measured in erg s-1.
Also measured in watts, where 1 watt = 1 x 107 erg s-1. Flux
density, the flux measured per unit area, is also often referred
to as "flux".
Erg - A cgs unit of energy equal to
work done by a force of 1 dyne acting over a distance of 1 cm.
107 (ten million) erg s-1 (ergs per second) = 1 watt. Also, 1
Calorie = 4.2 x 1010 (42 billion) ergs.
Effective Current - DC current that would produce the
same heating effects.
Effective Voltage - DC potential difference that
would produce the same heating effects.
Efficiency - Ratio of output work to input
Effort Force - Force extended on a machine.
Elastic Collision - Interaction between two objects
in which the total energy is the same before and after the
Elasticity - Ability of object to original
shape after deforming forces are removed.
Electrical Charge Pump - Device, often a battery or
generator, that increase potential of electrical charge.
Electrical Circuit - Continuous path through which
electrical charges can flow.
Electrical Current - Flow of charged particles.
Electrical Field - Property of space around a
charged object that causes forces on other charged objects.
Electric Field Lines - Lines representing the direction
of electric field.
Electric Field Strength - Ratio of force exerted by field
on a tiny test charge to that change.
Electric Generator - Device converting mechanical
energy into electrical energy.
Electric Potential - Ratio of electric potential
energy to charge.
Potential Difference - Difference in electric potential
between two points.
Electric Potential Energy - Energy of a charged body in an
Electromagnet - Device that uses an electric
current to produce a concentrated magnetic field.
Electromagnetic Induction - Production of electric field or
current due to change in magnetic flux.
Electromagnetic Radiation - Energy carried by electromagnetic
waves throughout space.
Electromagnetic Waves - Wave consisting of
oscillating electric and magnetic fields that move at speed of light through
Electromotive Force - Potential difference produced by
Electron Cloud - Region of high probability of
finding an electron around an atom.
Electron Diffraction - Effects on electrons due to
wave-like interference of electrons with matter.
Electron Gas Model - Description of current flow
Electroscope - Device to detect electric
Electrostatics - Study of properties and results
of electric charges at rest.
Electroweak Force - Unification of electromagnetic
and weak forces.
Elementary Charge - Magnitude of the charge of an
electron. 1.602 *10^ -19
Emission Spectrum - Spectrum produced by radiation
from excited atoms.
Energy - Non-material property capable of
causing changes in matter.
Energy Levels - Amounts of energy an electron in
an atom may have.
Entropy - Measure of disorder in a system;
ratio of heat added to temperature.
Equilibrant Force - Force needed to bring an object
into transitional equilibrium.
Equilibrium - Condition in which net force is
equal to zero. Condition in which net torque on object is zero.
Equivalent Resistance - Single resistance that could
replace several resistors.
Evaporation - Change from liquid to vapor
Excited State - Energy level of atom higher than
Forces - Forces exerted from outside a
Semiconductor - Semiconductor in which conduction
is primarily the result of added impurities.