How does GPS help predict volcanic eruptions? The ground swells slightly before an eruption. GPS devices can detect the swelling.
GPS satellites can see into the cone of the volcano.

The magma carries a GPS device as it travels. Scientists can track the flow of magma by adding more GPS devices to magma.

GPS devices can detect when gases leave a volcano before an eruption.

the answer would be a

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.