L1 - Lighting Pop Quiz

Question 1

Name 4 factors that affect visibility

Answer 1

• Size
• Brightness
• Contrast
• Time

Question 2

What is another name for colour temperature?

Answer 2

Chromacity

An objective specification of the quality of a color regardless of its luminance.

Question 3

What are the three primary colors

Answer 3

Red, green and blue

Question 4

What is the CRI and what does it express?

Answer 4

CRI - Color Rendition Index

Expresses the ability of a light source to portray color to a reference

Question 5

What is Luminous Flux?

Answer 5

Quantity of light output from source.
Define the time rate flow of light.
Unit: Lumen

• 1 Lux = 10.76 Lumen
• 1 Lux = 1 Lum / SQ m
• E (Lux) = I (light intensity in Candella) / D^2 (distance in metres)

Question 6

What is Luminous Flux Density?

Answer 6

• Luminous flux per unit area at a point of surface.
• The illumination on a surface
• Unit: Lx ( Lux)
• 1 Lux = 10,76 Lumen
• 1 Lux = 1 Lum / S Q m

Question 7

What does the term efficacy mean?

Answer 7

The ratio of light output ( Lumen) to light input ( in Watts)

Question 8

What color is the human eye most sensitive to?

Answer 8

Yello and Green ranges

Question 9

What instrument is the the used of measure lighting levels?

Answer 9

Photometer; Luxmeter

Question 10

What does the term luminaire mean?

Answer 10

The complete light fixture, ballast, shade, bulb etc

Question 11

Name the 2 main causes of lighting loss

Answer 11

1 - Dirty fixture; luminaire dirt depreciation

2 - Lamp lumen depreciation

Question 12

The code consisting of a letter and a number refers to what with regard to bulb?

Answer 12

Shape and size

Question 13

Filaments are generally made up of what material?

Answer 13

Tungsten; used for electrical contacts and electrodes due its high melting point and low thermal expansion.

Question 14

What does the gas inside the incandescent bulb do?

Answer 14

• Reduces filament evaporation

Question 15

What is the inside of a frosted bulb coated with?

Answer 15

Silica powder

Question 16

What is the purpose of diffuse lighting?

Answer 16

To reduce glare and brightness

Question 17

Name these bulb shapes by code letter

Answer 17

S - Straight
F - Flame
PAR - Parabolic Aluminized
T - Tubular
G - Global

Question 18

The general service fixture comes in a number of different types of bases. Name them

Answer 18

• Medium
• Mogul
• Candelbra
• Intermediate

Question 19

Why do we wire the grounded conductor to the shell of a lamp holder?

Answer 19

• To prevent accidental shock

Question 20

Which produces more light?
3-50W or 1-150W bulb?

Answer 20

• 1-150w bulb
  -Higher efficacy ( Lumen per Watt)

Question 21

What is another name for a tungsten halogen lamp?

Answer 21

Quartz halogen

Question 22

A tungsten filament bulb is filled with what gas?

Answer 22

Argon

Question 23

Explain the regenerative cycle of the tungsten halogen bulb

Answer 23

• Tungsten evaporates and halogen gas combines to return it to the filament.

Question 24

Why is necessary not to touch the bulb with your fingers?

Answer 24

• Oils from the skin damage the bulb features

Question 25

What type of switch does the code require for switching lights?

Answer 25

‘ T ’ type [14 - 508 (b) ]

Question 26

What does the Code say with regards to switching the grounded conductor?

Answer 26

- Only switch the underground conductor

Question 27

Where is a lighting contactor required?

Answer 27

When you have a large bank of lights

Question 28

In fluorescent lighting, what material is used in the tube to assist in the initiation of current flow?

Answer 28

Argon gas

Question 29

What material is used in the tube to transform UV radiation into visible light?

Answer 29

Phosphor coating

Question 30

Name 3 types of fluorescent tubes

Answer 30

- Circline - Straight - U-Shaped

Question 31

Name 3 types of fluorescent tubes bases

Answer 31

- Single pin - Double pin - Recessed socket

Question 32

Name 3 types of ballasts used in fluorescent lighting

Answer 32

- Preheat - Instant start - Rapid start

Question 33

Why do we not used single tube fluorescent fixtures around moving machinery?

Answer 33

- To reduce the stobe effect of the tube

Question 34

Low pressure sodium lamp have an efficacy close to what?

Answer 34

200 lumens

Question 35

The spring loaded socket end of a fluorescent fixture is the X voltage end.

Answer 35

HIGH

Question 36

What does OCV stand for

Answer 36

Open Circuit Voltage; refers to voltage across the terminals of a battery when the circuit is open ( the battery is not under load).

Question 37

What is the major cause of ballast failure?

Answer 37

Ambient heat

Question 38

What does HID stand for?

Answer 38

High Intensity Discharge, which indicates that bulbs are brighter than standard headlights.

Question 39

Which type of HID lighting has the best color rendition

Answer 39

Metal halide

Question 40

What is the physical difference between metal halide and mercury vapour bulbs?

Answer 40

Metal halide tube is smaller in size

Question 41

Name the bulbs by letter code

Answer 41

B - bullet BT - Bulged tubular E - Elliptical PAR - Parabolic Aluminized Reflector T - Tubular

Question 42

What does ANSI stand for?

Answer 42

American National Standards Institute

Question 43

Interpret this code: H36 BT-1000/DX

Answer 43

H - Mercury 36 - Ballast BT - Bulged Tubular 1000 - 1000Watts DX - Deluxe

Question 44

Name three type of ballasts and describe how they work.

Answer 44

- Reactor: . Used only with mercury vapour . Sometimes called a ‘lagr’ reactor . Suitable when line voltage is suitable for striking voltage . Acts as a choke . 240240 v or greater - Autotransformer . Used with mercury vapour . Voltage doesn’t vary more than 5% . Larger and more expensive - Auto Regulator . Metal Halide . Allows for voltage dips of 40-50% without ‘extincisline’ the bulb

Question 45

What is the fundamental difference between HPS and the other HID lights?

Answer 45

HPS has no starting electrode ‘Both Metal Halide and High Pressure Sodium bulbs are part of the HID family of bulbs. The primary visual difference between them is that metal halide light is white and the light emitted from a High Pressure Sodium bulb is amber orange. The lamp works by creating an electric arc through vaporized sodium metal.’

Question 46

What happens when you have a ballast that has 2 bulbs in series and 1 bulb goes out?

Answer 46

They both go out