Why there are tube lights installed in pair in offices?

Question

I have always seen tube lights are being installed in pairs in offices. I remember I read about this somewhere and has a scientific reason, but could not recall it.

Answer 1

If you mean fluorescent tubes, it's just a convenient and practical design choice.  The ballast is the most expensive part of the fixture, so it's practical to share a ballast between 2 or more bulbs.  4 is also common.

Answer 2

they dont have to be installed in pairs. what matters is the ballast which is a type of transformer. a ballast is used to fire vapor lights (metal halide, sodium vapor, neon, florescent, etc). ballasts take the incoming power and convert it to a voltage useful to fire the light (sometimes 10s of thousands of volts). if a ballast is made to run two lights at once, both lights should be changed at the same time. if they are not, it can create an imbalance in the ballast. this imbalance wont hurt anything. at worst it uses a little more power or cant fire one of the bulbs. also matching two identical bulbs increases their life span (just like batteries). also, the bulb that has not burnt out yet probably will soon.

to answer your question, it is cheaper in the long run to replace both because of the amount of power consumed, extending the life of the bulbs and the cost of paying some one tho replace both bulbs as opposed to just one.

Answer 3

      For better illumination of course and at the same time it is connected in parallel so that in case one flicks out , the other can still give light.