stable atom
atom with equal # of protons and electrons
electron shell
where electron orbits atom
flow of electricity through conductor
capacity of electrical system to do work
measurement of electrical change between two bodies
3 wires in AC circuit and what they’re used for
green-ground; white-neutral; black-hot
what ohm’s law measures
resistance in a circuit
why light can be considered a particle
travels in straight lines and can travel through a vacuum
properties of a wave
diffraction, reflection, refraction
what does diffraction mean?
waves fill in behind obstruction
what does refraction mean?
waves bend as they pass from one medium to another
point of incidence
where light strikes surface of reflector
angle of reflection
angle between normal and reflected angle
what does an ellipsoidal reflector do?
redirects light rays to a secondary point
what is the focal length of a lens?
distance from optical center to principal foci
what type of lens is a plano convex lens?
positive spherical
conventional fixtures commonly used in theatre
ERS, leko, fresnels, par cans, cyc lights, strip lights, follow spots
what does ERS stand for?
ellipsoidal reflector spotlight
what are ERS fixtures commonly used for?
front lights, key lights, specials
what was the fresnel lens ORIGINALLY developed for?
what type of reflector is used in a fresnel fixture?
what type of reflector is used in a par lamp?
PARABOLIC aluminized reflector
how do you focus a par can?
rotate the lamp
what are par cans typically used for?
wash lights