811. How many zones through which the charge passes in a rotary kiln ?
A. 4
B. 3
C. 2
D. 5

812. Which one of the following set of raw material is most suitable for manufacture of urea ?
A. CH4 N2 and CO2
B. H2 N2 and CO
C. H2 CO2 and H2O
D. H2O N2 and H2

813. The percentage of nitrogen in urea is________________?
A. 36%
B. 46%
C. 56%
D. 66%

814. Which one of the following fertilizers provides the nitrogen and phosphorus to the plant ?
A. urea
B. calcium superphosphate
C. diammonium phosphate
D. potassium nitrate

815. Cement is a mixture of________________?
A. clay and clinker
B. clay lime stone and gypsum
C. lime stone and gypsum
D. lime stone and clay

816. Cement is a mixture of so many compounds roasted in rotary kiln. Which substances has greater percentage ?
A. Lime (CaO)
B. Silica (SiO2)
C. Alumina (Al2O3)
D. Magnesia (MgO)

817. Which sequence of steps is correct for the manufacture of cement ?
A. crushing heating mixing grinding
B. crushing mixing heating grinding and mixing
C. crushing grinding mixing heating
D. mixing heating grinding crushing

818. The composition of mixture of clay and lime stone in the raw for cement material is __________________?
A. 75% lime stone and 25% clay
B. 25% lime stone and 75% clay
C. 15% lime stone and 55% clay
D. 55% lime stone and 15% clay

819. The important function of burning zone in the rotary kilm is __________________?
A. to dry the moisture of slurry
B. to decompose lime stone to unslaked lime
C. combination of different oxides like CaO SiO2 Fe2O3 and Al2O3
D. to reduce the impurities

820. Which of the following is incorrect statement about nitrogen importance ?
A. It enhances plant growth
B. It is involved in the synthesis of protein and nucleic acids
C. it accelerates fruits and flowers growth
D. It is involved in the chlorophyll synthesis