821. Which of the following is macronutrient ?
A. Cu
B. Cl
C. H
D. Zn

822. Which of the following is the most suitable catalyst for ammonia synthesis ?
A. Pt
B. ZnO + Cr2O3
C. Fe in fused mixture of Al2O3 + SiQ2 + MgO
D. All of the above

823. Which of the following fertilizers is not useful for paddy rice ?
A. urea
B. DAP
C. Ammonium sulphate
D. Ammonium nitrate

824. Which of the following potassium fertilizers are more useful for horticultural crops tobacco & potatoes ?
A. KCI
B. KNO3
C. K2SO4
D. KMnO4

825. Argillaceous material does not include________________?
A. vlay
B. marine shells
C. slate
D. blast furnace slag

826. The nutrients which are required in very small amount for the normal growth of plants are called_________________?
A. nitrogenous fertilizers
B. micronutrients
C. phosphorus fertilizer
D. all of the above

827. Which one of the following is an inorganic fertilizer ?
A. manure
B. urea
C. ammonium nitrate
D. All

828. The potassium present in plant help the plant to___________________?
A. form starch sugar and fibrous material
B. ripen the seeds and fruits
C. increase the resistance against disease
D. all the above statements are correct

829. What is clinker ?
A. roasted calcareous material
B. roasted argillaceous material
C. roasted calcareous and argillaceous material
D. roasted gypsum

830. Phosphorus helps in the growth of_________________?
A. root
B. leave
C. stem
D. seed