Light and Illumination Concepts Quiz
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Questions and Answers

Which phenomenon refers to the reflection of light when it bounces off a shiny surface?

  • Diffusion
  • Refraction
  • Reflection (correct)
  • Transmission

    • Light is always refracted when it passes through any material.

    False

    What is the term for light that is absorbed by opaque materials?

    Absorption

    The phenomenon where light is made to travel in a single plane is known as _______.

    <p>polarization</p> Signup and view all the answers

    What is the initial lumen output of a lamp?

    <p>The rated light output when the lamp is new</p> Signup and view all the answers

    Match the following light control characteristics with their definitions:

    <p>Reflection = Light bouncing off a surface Diffusion = Scattering light in multiple directions Transmission = Light passing through a material Refraction = Change in light direction at a material interface</p> Signup and view all the answers

    In polarization, light can pass through all polarizing materials without any effect.

    <p>False</p> Signup and view all the answers

    What property of light allows it to change direction when it passes from air into glass?

    <p>Refraction</p> Signup and view all the answers

    What is defined as the time elapsed when 50% of a group of lamps remain burning?

    <p>Rated lamp life</p> Signup and view all the answers

    Mean lumens refers to the lumens output at 100% of the rated life of the lamp.

    <p>False</p> Signup and view all the answers

    What is the term for the ratio of total light output of the lamps versus the output of all lamps in the luminaire?

    <p>Luminaire efficiency</p> Signup and view all the answers

    The loss of light output with time is known as __________.

    <p>lumen depreciation</p> Signup and view all the answers

    Which measurement indicates how well a lamp renders colors compared to a reference light source?

    <p>Color rendering index (CRI)</p> Signup and view all the answers

    Match the following terms with their definitions:

    <p>Luminous efficacy = Light output per unit of electrical power Color temperature = Color of lamp expressed in kelvins Flicker = Light fluctuations due to cyclical current Beam lumens = Initial lumens output within the central beam</p> Signup and view all the answers

    Flicker is normally perceptible in coated HID lamps due to their characteristics.

    <p>False</p> Signup and view all the answers

    What is the term used to describe the light output within the central beam of a floodlight?

    <p>Beam lumens</p> Signup and view all the answers

    What is one way to minimize light intensity in lamps?

    <p>Using lead lag ballast</p> Signup and view all the answers

    Inert gas is used in a bulb to increase the evaporation rate of the filament.

    <p>False</p> Signup and view all the answers

    What type of base is fitted with a screw pitch for insertion into a socket?

    <p>Screw base</p> Signup and view all the answers

    The _____ is a decorative bulb that can be used with dimmers or as accent lighting.

    <p>Candle</p> Signup and view all the answers

    Which of the following is NOT a type of incandescent lamp mentioned?

    <p>LED</p> Signup and view all the answers

    Match the following components to their descriptions:

    <p>Filament = Emits light rays when current passes through Base = Metal end of a light bulb for socket connection Heat deflecting disc = Protects the base from heat Lead-in wire = Electric conductor to the filament</p> Signup and view all the answers

    Extended life service bulbs are designed to operate at temperatures significantly lower than 3800°F.

    <p>True</p> Signup and view all the answers

    What is the expected life span of heavy filament incandescent lamps in extended life service?

    <p>2500 to 10,000 hours</p> Signup and view all the answers

    What is the primary advantage of using dichroic reflector lamps?

    <p>They allow selective color transmission.</p> Signup and view all the answers

    Krypton lamps are known for their longevity and high color rendition.

    <p>True</p> Signup and view all the answers

    What component of a light bulb connects it to the electric circuit?

    <p>Base</p> Signup and view all the answers

    The gas inserted in the bulb to slow down the evaporation of the filament is called __________.

    <p>inert gas</p> Signup and view all the answers

    Which type of lamp achieves better energy efficiency than standard incandescent bulbs?

    <p>Tungsten halogen lamps</p> Signup and view all the answers

    Match the type of lamp with its characteristic.

    <p>Dichroic reflector lamp = Transmits color selectively Krypton lamp = Long life and good color rendition Miniature reflector lamp = High efficacy and great color quality Mercury lamp = Uses liquid mercury for vapor</p> Signup and view all the answers

    Mercury vapor lamps require high voltage for operation.

    <p>True</p> Signup and view all the answers

    What is the primary role of the filament support in a light bulb?

    <p>Hold the filament in place</p> Signup and view all the answers

    What is the primary purpose of the emitter material in a cathode coil?

    <p>To emit electrons</p> Signup and view all the answers

    Argon is the only inert gas used in fluorescent lamps.

    <p>False</p> Signup and view all the answers

    What material is the basic phosphor in white fluorescent lamps?

    <p>Calcium halophosphate</p> Signup and view all the answers

    The ______ is used to connect the lamp to the electric circuit.

    <p>base</p> Signup and view all the answers

    Which phosphor material is typically used to produce orange light?

    <p>Calcium silicate</p> Signup and view all the answers

    Match the following components with their functions:

    <p>Cathode Shield = Minimizes tube end blackening Ballast = Controls electrical resistance Bulb = Holds the gas Base = Connects lamp to electric circuit</p> Signup and view all the answers

    Rare earth phosphors improve lumen maintenance characteristics.

    <p>True</p> Signup and view all the answers

    How much can rare earth phosphors potentially raise lumen output over conventional halophosphors?

    <p>Up to 8%</p> Signup and view all the answers

    What is the main function of a ballast in fluorescent lamps?

    <p>To start the lamp and regulate the current</p> Signup and view all the answers

    Instant start lamps require the electrodes to be heated before operation.

    <p>False</p> Signup and view all the answers

    What is the ballast factor used for?

    <p>To determine the light output for a specific lamp-ballast system relative to rated lumen output.</p> Signup and view all the answers

    The __________ of a fluorescent lamp ballast indicates how efficiently it converts electrical power into usable light.

    <p>efficacy</p> Signup and view all the answers

    What causes the hum emitted by electromagnetic ballasts?

    <p>Vibration of the laminated core</p> Signup and view all the answers

    Match the following types of lamps with their characteristics:

    <p>Rapid start lamps = Have low resistance cathodes and heat continuously Instant start lamps = Do not heat electrodes prior to starting Preheat lamps = Require initial heating before starting Triphosphor lamps = Lower depreciation of luminous flux</p> Signup and view all the answers

    Fluorescent lamps are highly efficient and convert a large percentage of input power to light without producing waste heat.

    <p>False</p> Signup and view all the answers

    What are harmonics in relation to current or voltage wave shapes?

    <p>Harmonics are sinusoidal voltages or currents that are higher multiples of the fundamental frequency.</p> Signup and view all the answers

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