What overall effect does adding a catalyst have on a chemical reaction?

The overall effect of a catalyst to the reaction is that it lowers the activation energy of a chemical reaction. Catalyst is a substance that speeds a chemical reaction. It is not consumed as the reaction proceeds. A catalyst offers a new route for faster reaction. 

what is the question here. i think you messed up.

on passing the small ampere of electric current through the tube made of ar and hg of cfl generates uv rays which excites the fluorescent and thus emits the high radiation by consumption of just 5- 12 w in comparison to incandescent light which requires more power such as around 40 - 55 w to lighten.

moreover the life span of fluorescent or cfl is around 8000 h whereas the life span of incandescent is around 1200 h

hence, the building installed with incandescent lights bears more electricity bill.