The society of automotive engineers has established an accepted numerical scale to measure the viscosity of motor oil. for example, sae 40 motor oil has a higher viscosity than an sae 10 oil. rank the following hydrocarbons by their expected viscosity.

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.