The elevator shall be equipped with a __________ to cut off all power to the elevator if the upper normal terminal stopping devices fail.

The distance, measured in the direction of propagation of a wave from any one point to the next point of corresponding phase.

A predominant frequency of a sound as perceived by the human ear.

The sensation stimulated in the organs of hearing by mechanical radiant energy transmitted as longitudinal pressure waves through the air or other medium.

A subject response to sound indicating sensation produced by the amplitude of a sound wave.

A unit for measuring the apparent loudness of a song, equal in number to decibels for a 1000-hz reference sound judged by a group of listeners to be equal in loudness to the given sound.

A range of frequency from 15Hz to 20,000 Hz audible to the normal human ear.

The difference between actual pressure at any point in the field of a sound wave and the static pressure at the point, expressed in Pascals.

The branch of physics that deals with the production control transmission reception and effects of sound.

Airborne sound traveling directly from a source to the listener.

One of a number of acoustic panels installed near the ceiling of a concert hall to reflect sound for improving the acoustic quality of music.

A unit sound absorption, equal to one sq. ft. (0.09 sqm) of a perfectly absorptive surface.

The interception and conversion of sound energy into heat or other form of energy by the structure of a material

The use of the building materials and construction assemblies designed to reduce the transmission of airborne and structure borne sound from one room to another or from the exterior to the interior of the building and it’s also called_____.

A resilient base for mechanical equipment, installed to reduce the transmission of vibration and noise to the supporting structure.

A path for the transmission of sound other than through a floor, wall or ceiling assembly, as long such interconnecting structure as ductwork or piping.

This Acoustical Defect is due to large amounts of highly reflective surfaces and/or to large volume of space which will take considerable time for reflected sound to die out.

Distinct reflection of original sound which results when the path of reflected sound is 20 m (65 ft) or more than the path of direct sound.

A rapid but repetitive succession of sounds caused by highly reflective parallel surfaces.

A noise whose energy is uniform over a wide range of frequencies. This is analogous to the term "white light", which consists of almost equal amount of light of different wavelength.

Also Known as Ambient Noise.

A noise created by collision of two objects.

Sound travels in space by a phenomenon called _________________.

Exterior Background noise in a neighborhood.

It is a brand new technology, rather than emitting all the colors of the rainbow and a lot of blue light, they emit mostly in the yellow.

It is commonly use in streetlights, parking lot lights and stadium lights. They are very bright and contribute to a lot of light pollution and fairly efficient. They produce very white light having a good color rendition, meaning that objects under these lights are showing their true color.

It produces light when a thin wire called tungsten filament is heated by electricity running through it making it so hot that it starts to glow brightly. This releases a lot of heat and the bulbs get hot to touch, meaning this bulb is very inefficient.

When the tungsten burns off the filament, the gas re-deposits it back onto the filament to be reuse. These bulbs last longer and much brighter.

It is the most commonly used street light. It produces light by running electricity through a mixture of gases, which produces light. The lamp itself is preferred because it requires little maintenance and fairly efficient. They take a while to turn on completely and produce a yellow-orange glow.

It is a type of electric lamp that is widely used in commercial, residential, and transportation illumination. It produces a highly directional beam.

A reflector bulb of blown glass for incandescent and high-intensity discharge lamps, having an internal reflective coating and either a clear or frosted glass front to provide the desired beam spread.

A source of artificial light that employ advanced technology to reduce the amount of electricity used to generate light, relative to traditional filament-burning light bulbs.

Unit of Luminous Intensity of a light source in a specific direction.

A type of Light color temperature which is best for bedrooms and living rooms; providing a traditional warm, cozy feel to them.

Unit of light intensity, measured in lumens per square foot.

Unit of light flow or luminous flux.

A type of Light color temperature which is best in kitchens, bathrooms or garages; giving rooms a whiter, more energetic feel.

The amount of light or density of luminous flux striking a unit are

A type of Light color temperature which is best in bathrooms, kitchens and basements; good for reading, intricate projects, or applying makeup-provides the greatest contrast among colors.

Lighting in which luminaires distribute 90% to 100% of the emitted light downward on the surface or area to be illuminated.

Lighting in which luminaires distribute 60% to 90% of the emitted light downward.

Lighting from luminaires that emit an approximately equal distribution of light upward and downward.

Lighting in which luminaires distribute 60% to 90% of the emitted light upward.

Lighting in which luminaires distribute 90% to 100% of the emitted light upward, especially to avoid glare or prevent shadows.

The simplest method of support for lighting is where the fittings are mounted directly on to a ceiling or wall structure; where the ceiling or wall must be of sufficient structural stability.

These are a traditional means of lighting for very good reasons, having easy access for cleaning and maintenance at a low level and having the added advantage of a general distribution of light. The pendant method of hanging a light fitting from the ceiling or roof.

Lighting provided by adjustable spotlights mounted along a narrow ceiling or wall mounted metal track through which current is conducted.

Defined as lighting systems where the sources are hidden from view by the fabric of the building and they are generally thought of as a way of providing indirect lighting to walls or ceilings.

A luminaire having a trough-shaped reflector holding one or more fluorescent lamps.