Question

The ballast factor of a fluorescent lamp is given as 0.90 . The fixture contains 4 lamps, each rated at 15 watts and 825 lumens. The ballast consumes 3 watts.

How many lumens will be produced per lamp, and what is the total wattage of the fixture?
a. 742.5 Lument per lamp and 54 watts per fixture
b. 742.5 Lument per lamp and 57 watts per fixture
c. 825 Lument per lamp and 63 watts per fixture
d. 916.6 Lument per lamp and 66.6 watts per fixture

Answer 1

The lumens produced per lamp with a 0.90 ballast factor is 742.5 lumens, and the total wattage for the fixture, including the ballast is 63 watts.

Step-by-step explanation:

To calculate the resulting lumens per lamp with a ballast factor of 0.90 and a fixture that has 4 lamps, each rated at 15 watts and 825 lumens, we must multiply the lumens rating by the ballast factor:

Lumens per lamp = Rated lumens × Ballast factor = 825 lumens × 0.90 = 742.5 lumens per lamp.

To compute the total wattage of the fixture, we add the wattage of all the lamps and the ballast:

Total wattage = (Wattage per lamp × Number of lamps) + Ballast wattage = (15 watts × 4) + 3 watts = 60 watts + 3 watts = 63 watts per fixture.

Therefore, the correct answer is a. 742.5 Lumens per lamp and 63 watts per fixture.