UPSC CSE Prelims 2015 Q18 — Environment & Ecology PYQ with Answer

With reference to ‘fly ash’ produced by the power plants using coal as fuel, which of the following statements is/are correct?

1. Fly ash can be used in the production of bricks for building construction.

2. Fly ash can be used as a replacement for some of the Portland cement contents of concrete.

3. Fly ash is made up of silicon dioxide and calcium oxide only, and does not contain any toxic elements.