Lighting

Question 1

What is the measurement of light quality?

Answer 1

Colour temperature, degrees Kelvin (°K),

Question 2

Colour temperature:

Sources with low colour temperatures - below 3,000 °K
- have “_______“ colour

Answer 2

Warm (red and yellowish

Question 3

Colour temperature:

sources with high colour temperatures - above 4,000 °K
- have “_______” colour

Answer 3

Cool (bluish)

Question 4

_____________ is the ability of a light source to portray the colour appearance of objects accurately when compared to a standard (reference) light source of the same colour temperature.

Answer 4

Colour rendition (CRI)

Question 5

with no losses (100% efficacy 1 watt would produce about _________ Lumens

Answer 5

683

Question 6

measurement of lumens per watt (Lm/W) is a manner of expressing the __________ of a
light source in converting electrical energy into light.

Answer 6

efficiency

Question 7

The choice of the light source for luminaires is:

Answer 7

-incandescent
-fluorescent
-high-intensity discharge (HID)
-low-pressure sodium
-LED

Question 8

The accumulation of dirt on lamps and fixtures can cause light losses of 30% or more

Answer 8

Luminaire Dirt Depreciation

Question 9

The light output of a lamp decreases with age, the wattage input does not.

Answer 9

Lamp Lumen Depreciation

Question 10

What advantage does the ordinary fluorescent lamp have over the incandescent lamp?

Answer 10

It is more efficient at converting electrical energy into light energy

Question 11

How is visible light obtained in the fluorescent lamp

Answer 11

In two stages: electrons collide with mercury atoms to produce UV radiation then the Phospor coating shifts the wavelength into visible light

Question 12

What two purposes does the ballast in a fluorescent fixture serve?

Question 13

Fluorescent fixture are classified according to their method of starting. Name three classes:

Answer 13

1. Pre-heat
2. Instant-start
3. Rapid-start

Question 14

How does frequent switching on and off affect a fluorescent lamp?

Answer 14

Shortens their life

Question 15

fluorescent lamp come with different base types. List three common type:

Answer 15

double pin, single pin recessed and double contact

Question 16

What do the letters “HO” and “SHO” refer to in connection with fluorescent lamp identification?

Answer 16

High Output, Super higher output

Question 17

List 2 method for reducing stroboscopic effects in fluorescent lighting circuits:

Answer 17

Any two of the following: use lead-lag ballasts, connect to different phases of a three-phases system, use a steady light source such as an incandescent or LED lamp.

Question 18

Of the three types of fluorescent fixtures, which ballast puts out the highest starting or striking voltage?

Answer 18

instant start

Question 19

What is the main purpose of a capacitor used in rapid-starting fluorescent lamp fixtures?

Answer 19

To help provide striking voltage to the lamp

Question 20

A ballast used for a 2-lamp fixture containing 4 ft. lamps is also suitable for use in a 2-lamp8 ft. fixture True or False

Answer 20

False, the 8ft lamps would likely require a higher striking voltage

Question 21

Blackening of the ends of a fluorescent lamp is ordinarily a sign of what?

Answer 21

The lamp is nearing the end of its useful life.

Question 22

The two most fundamental measurements of light deal with:

Answer 22

Quantity and Quality

Question 23

The tungsten-halogen lamp is a special type of incandescent lamp.
It is a compact, high intensity light source that provides a _______ light
output with high lumen maintenance

Answer 23

white

Question 24

The most common size of fluorescent lamp, in the past, was the

Answer 24

4’ T12 (11 / 2 “) diameter type

Question 25

The most common size of fluorescent lamp, at present, is the

Answer 25

4' T8 (1") diameter type

Question 26

The three bases most often used with fluorescent lamps are the

Answer 26

bipin, single pin, and recessed double-contact bases

Question 27

he rated life for most fluorescent lamps is in the ____ to ____ Hour range

Answer 27

7,500 to 20,000-hour range

Question 28

4 causes to reduce lamp life by:

Answer 28

1. switching too frequently 2. operating with the wrong type of ballast 3. using excessive supply voltage 4. losing cathode pre-heat during start-up

Question 29

A ballast with an “A” rating is _________ and a ballast with an “F” rating is _________.

Answer 29

quietest, noisiest.

Question 30

Special ___________ ballasts may be required to start a fluorescent lamp if the ambient temperature is too low.

Answer 30

cold weather

Question 31

A ballast should last ______ under normal operation.

Answer 31

12 to 15 years

Question 32

Major cause of ballast failure is __________

Answer 32

High ambient temperature

Question 33

Very high output lamps operate at 1,500 mA and are called "VHO" or "SHO" for super high output

Question 34

There are three main types of HID lamps:

Answer 34

-Mercury Vapor -Metal-Halide -High-Pressure sodium

Question 35

Rapid fluctuations of light can cause a ____________ in which moving objects are seen in repetitive flashes at successive positions

Answer 35

stroboscopic effect

Question 36

2 ways to avoid stroboscopic effect are

Answer 36

use lead-lag ballasts

Question 37

LED systems last up to __________ hours

Answer 37

50,000

Question 38

What is Coefficient of utilization

Answer 38

percentage of the initial lamp lumens that reach the task area to produce illumination

Question 39

Incandescent enery input is wasted in heat about ____% to __%

Answer 39

90% to 95%

Question 40

Why incandescent filament material is tungsten?

Answer 40

It has a high melting point (3,419°C) and a low rate of evaporation.

Question 41

What happen if the filament of incandescent operating full light out put for long periods of time?

Answer 41

Life span is reduce

Question 42

Quartz glass is used with tungsten-halogen lamps because......

Answer 42

it can very high temperatures.

Question 43

One 150 W lamp produces more light than three 50 W lamps. True of False

Answer 43

True

Question 44

higher filament temperatures produce greater efficacy and have a long service life

Answer 44

False, Higher filament temperatures produce greater efficacy but have a reduced service life

Question 45

To _________ the rate of filament evaporation, lamps of 40 W and higher are filled with________.

Answer 45

retard, inert gas

Question 46

_____________ is a special type of incandescent lamp. It is a compact, high intensity light source that provides a white light output with high lumen maintenance.

Answer 46

tungsten-halogen lamp (also called quartz-halogen lamp or quartz-iodine lamp)

Question 47

Fluorescent light is produced by a two-stage process. which is

Answer 47

1. electric current passes through a gas inside a glass tube and produces invisible ultraviolet (UV) radiation 2. The UV radiation is converted to visible light at the glass by a layer of phosphor powder which coats the inside surface of the fluorescent lamp.

Question 48

The tubes need to run for 100 hours to establish smooth, non-flickering working. this is called __________.

Answer 48

seasoning

Question 49

The life of a ballast is said to be reduced by ____ for each ____ temperature increase above its design temperature

Answer 49

50%, 10°C

Question 50

The average life of an LPS lamp is rated at __________

Answer 50

18,000 hours.

Question 51

High melting point of tungsten is ____________°C

Answer 51

3419°C

Question 52

What is start up time for Metal halide? How long do they last til?

Answer 52

5 to 7 minutes 15,000 hours

Question 53

How long does it take HPS to come to full brightness?

Answer 53

3 to 4 min

Question 54

HPS can have strike voltages in excess of 2500 OCV true or false

Answer 54

True

Question 55

what does DX mean? what does WDX mean?

Answer 55

White phosphor-coated (DX) Warm white deluxe phosphor-coated (WDX)