Projects & Experiments
Web Links
Teacher Guidlines
Site Map


Anode is a metal plate connected to a high potential (positive pole of a voltage source).

Atomic number denoted by Z is the number of protons found in the nucleus of an atom.

Atomic mass unit (a.m.u.) is a small unit of mass used in the context of atoms and smaller particles. It is defined to be 112 of the mass of one atom of carbon-12.

refers to the process of determining the relation between the output of a measuring instrument to the value of the input quantity. For example, a thermometer might be calibrated from an instrument that measures some other physical property than temperature.

is an electrical device that can store energy. It usually consists of a pair of metal plates close together, separated by an insulator.

is a metal plate connected to a low potential (negative pole of a voltage source).

Coaxial cable is an electrical cable consisting of a conducting wire, surrounded by an insulating spacer, surrounded by a copper mesh, usually surrounded by a final insulating layer. It is used for carrying electrical signals like those going to and from televisions.

Cathode rays are electrons emitted from the negatively charged plate in a discharge tube.

Diode is an electrical component that restricts the direction of movement of charged particles.

Discharge tube is a partially evacuated tube in which electrons travel whenever a suitable voltage is applied between the electrodes in the tube.        

Electrode is an metal conductor used to make contact with a nonmetallic part of a circuit.                                                

Electromagnetic waves are caused by the acceleration of charged particles. These waves involve electric and magnetic fields vibrating transversely and sinusoidally at right angles to the direction that the wave is travelling. The waves do not require a medium for propogation and travel through a vacuum at 300 million meters per second.

Electron is a tiny particle, which has negative charge.

Electron Volt (eV) is the energy acquired by an electron when it is accelerated by a potential difference of one volt.

Filament is a thin wire, usually tungsten, loosely coiled, used to convert electricity into heat and light in a light bulb.

means that the surface emits light of longer wavelength as a consequence of exposure to light of a certain wavelentgh.

Hertz: One hertz simply means "one cycle per second".

Induction coil is an electrical device used to produce high-voltage pulses from a low-voltage DC supply.

Kinetic Energy (KE) is the energy a body has by virtue of its motion.

Nucleus is a collection of protons and neutrons in the center of an atom that contains most of the atom's mass and has positive charge.

Neutron is an uncharged subatomic particle found in the nucleus.

Nucleon is a collective name for two particles found in atomic nuclei ...the proton and the neutron.

Periodic Table is a table of the elements arranged so as those elements with similar characteristics are in the same horizontal period or the same vertical group.

Phosphorescent materials do not immediately discharge the radiation they absorb.

Potential Energy (PE) is the energy a body has by virtue of its position.

Photoelectric effect is the emission of electrons from the surface of a metal when light of sufficiently short wavelength is incident on the metal.

Quantum Mechanics is the branch of physics that interprets physical phenomena occuring on a very small scale (e.g. the motion of electrons).

Rectification is the conversion of alternating current to direct current, using a (semi-conductor) diode or vacuum tube.

Scope probe is a physical device used to connect an oscilloscope to a piece of equipment under test.

Space charge is a localized region of negative charge that occurs near a metal when it is heated in a vacuum tube.

Stopping potential is the voltage needed to stop the most energetic electrons from reaching the collector.

Thermionic diode is a device generally used to amplify an electrical signal by controlling the movement of electrons in an evacuated space.

Thermionic emission is the emission of electrons from the surface of a metal when the metal is heated.

Transformers are electrical devices that transfers energy from one circuit to another. It has no moving parts. A transformer consists of two coils wound on a soft iron core. An alternating current in one coil induces a changing magnetic flux in the core which in turn induces an alternating current in the second coil. Transformers are used to step up or step down alternating voltages.

Vacuum pump is a pump that removes gas particles from a sealed container in order to leave behind a partial vacuum.

Voltage is a measure (in volts) of the potential difference between two parts of aVacuum pump n electrical circuit.