Question

Question 11 (1 point)

An LED has reached the end of rated life when:

Question 11 options:

	the filament opens.
	the fill gas is allowed to escape.
	emissive material on the cathode is insufficient to start or maintain the electrical discharge.
	lumen output drops 30 percent from initial rated value.
	the mercury beads have been vaporized.

Question 12 (1 point)

Based upon the operating conditions, it is determined that it is necessary to change a LED lamp 0.05 times over a year. If there are 100 such lamps and they cost $25.00 each, the estimated lamp replacement cost for the year is:

Question 12 options:

	$0.05.
	$1.25
	$96.00.
	$2,500.00.
	$125.00.

Question 13 (1 point)

As an LED reaches the end of it’s rated life:

Question 13 options:

	it will have darkening around the lens, from vaporized tungsten atoms being deposited on it.
	will blink on and off as the arc stream becomes more difficult to maintain.
	the colors produced will have a cooler correlated color temperature (CCT).
	the arc tube may rupture.
	lumen production will stay steady.

Question 14 (1 point)

Increasing the junction temperature of an LED 10^oC beyond its rated temperature, will result in:

Question 14 options:

	an increase in the rated life.
	an increased lumen production in cold weather.
	an improvement in cold weather starting.
	a decrease in expected life.
	greater cathode evaporation.

Question 15 (1 point)

An LED needs a device to limit current flow through the semiconducting die material. This device is called a(n):

Question 15 options:

	loper.
	electronic control gear.
	drover.
	driver.
	ballast.

Question 16 (1 point)

The light output of a light emitting diode (LED) is primarily dependent on lamp wattage and:

Question 16 options:

	current flow through the semiconducting die material.
	inert gas.
	globe size.
	percent of halogen gas fill.
	ambient temperature surrounding the lamp.

Question 17 (1 point)

Correlated color temperature (CCT) along with color rendition index (CRI) are used to determine the appearance of objects when illuminated under the light source. CRI varies from 0 to 100. Which of the following statements is correct?

Question 17 options:

	A CRI of 0 is always desired.
	A CRI of 100 is always desired regardless of lamp cost.
	A lower CRI makes a wide variety of colored objects appear more natural in color.
	A higher CRI makes a wide variety of colored objects appear more natural in color.
	A SP30 lamp with a CRI of 100 will produce pure white light.

Question 18 (1 point)

A storage area is lighted with 20 LED lamps. Each lamp has a medium screw shell base and an internal driver that is concealed in the lamp. If each lamp is rated 30 watts, the estimated power consumed is:

Question 18 options:

	600 kW.
	0.6 kW.
	0.7 kW.
	10 kW.
	0.8 kW.

Question 19 (1 point)

A storage area is lighted with eight luminaires. Each luminaire is a single-lamp, electrode-less fluorescent fixture. The lamps are operated by an external ballast and each lamp is rated 250 watts. If the lights are expected to be operated for 2,000 hours a year, and the energy cost is $0.14-kWh, the cost of energy to operate lamps for a year is:

Question 19 options:

	$161.00.
	$256.00.
	$560.00.
	$644.00.
	$952.40.

Question 20 (1 point)

Of the following, the lamp whose life is most affected by frequent starting is the:

Question 20 options:

	incandescent.
	fluorescent.
	induction (electrode-less fluorescent).
	light emitting diode.
	tungsten-halogen incandecent.

Answer 1

11) Lumen output drops 30% from initial rated value.

12) $125 because

   one lamp corresponds to 0.05 times; Therefore 100 lamps corrsponds to 0.05x100=5 times. Hence cost of replacing in ayear=5x25=125 dollars.

13) It will have darkening around the lens, from vaporized tungsten atoms being deposited on it.

14) A decrease in expected life.

15) An Electronic control gear.

16) ambient temperature surrounding the lamp.

17) A higher CRI makes a wide variety of colored objects appear more natural in color.

18) 0.6 kW(because 20x30=600 W=0.6 kW)

19)

20) Flourescent lamp.