NDA2025General AbilityGeneral ScienceActual
Which one of the following is NOT present in cement?
Options
- A2CaO SiO₂
- B3CaO SiO₂
- C4CaO SiO₂
- D3CaO Al₂O₃
Correct answer
C. 4CaO SiO₂
Step-by-step solution
Portland cement is a complex mixture of silicates and aluminates of calcium. The main constituents of Portland cement are: Dicalcium silicate ( 2CaO SiO₂ ) Tricalcium silicate ( 3CaO SiO₂ ) Tricalcium aluminate ( 3CaO Al₂O₃ ) Tetracalcium aluminoferrite ( 4CaO Al₂O₃ Fe₂O₃ ) Tetracalcium silicate ( 4CaO SiO₂ ) is not a constituent of cement. Answer: 4CaO SiO₂