A. They are more regular in shape and dense
B. They are more regular in shape and highly porous
C. They are more irregular in shape and porous
D. They are more dense and prismatic in shape
Related Mcqs:
- Beta hemihydrate particles absorb______________?
A. More water
B. Less water
C. no water
D. None of the above - The strength of the gypsum specimen when the water in excess of that required for the hydrate of the hemihydrate is left in the specimen is called____________?
A. Dry strength
B. Green strength
C. Water strength
D. Compressive strength - The product, which is obtained by calcining gypsum under steam pressure at 120-130°C or by dehydrating gypsum in the presence of sodium succinate is_______________?
A. Alpha – hemihydrates
B. Beta – hemihydrates
C. Calcium sulphate dihydrate
D. Orthorhombic anhydrate - Water powder ratio of dental stone and plaster is respectively_________________?
A. 0.28 and 0.6
B. 0.6 and 0.28
C. 0.6 and 3.2
D. 0.28 and 0.98 - The water powder ratio of alginate is______________?
A. 100 ml of water to 60 gms of powder
B. 40 ml of water to 40 gms of powder
C. 40 ml of water to 15 gms of powder
D. 15 ml of water to 40 gms of powder - Accelerators and retarders are used with gypsum products mainly to control_______________?
A. Setting time
B. Setting expansion
C. Hardness of the set product
D. None of the above - Modiffiers are added to gypsum mainly to_______________?
A. Modify setting time
B. Modify setting expansion
C. Modify strength
D. Decrease the porosity - ADA specification number of gypsum products are described under____________?
A. 1
B. 4
C. 12
D. 25 - Type III Dental gypsum is__________________?
A. Class II stone
B. Densite
C. Class I stone or hydrocal
D. Model or lab plaster - Gypsum product having least expansion_____________?
A. Impression plaster
B. Model plaster
C. Stone plaster
D. Die stone
