A. Produce a smoother casting
B. Decrease setting expansion
C. Increase setting expansion
D. Increase thermal expansion
Related Mcqs:
- Gypsum bonded investment should not be heated over______________?
A. 700°C
B. 1,300°C
C. 1,063°C
D. 900°C - Quartz is added to gypsum bonded investment to______________?
A. Increase the strength
B. Counter balance contraction of gypsum during heating
C. aid in hygroscopic expansion
D. Increase the shelf life of investment - The best pickling solution for gypsum bonded investment is_______________?
A. Hydrochloric acid
B. Nitric acid
C. Sulphuric acid
D. Phosphoric acid - 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 - Binder in phosphate bonded investment is______________?
A. Magnesium oxide & Phosphate
B. Magnesium oxide & Phosphoric acid
C. Magnesium oxide & Monoammonium phosphate
D. Magnesium oxide & Ortho Phosphoric acid - Binder used in Gypsum investment is_________________?
A. Silica
B. Quartz
C. Cristobolite
D. Calcium sulphate monohydrate - The strength of a gypsum investment is dependent on_______________?
A. Carbon content
B. Silica content
C. Gypsum
D. Copper - The most commonly used accelerator in gypsum product is___________________?
A. Sodium fluoride
B. Potassium fluoride
C. Potassium sulfate
D. Aluminium sulfate - ADA specification number of gypsum products are described under____________?
A. 1
B. 4
C. 12
D. 25 - As per DNA No. 25, minimum amount of setting expansion required for type V gypsum products_______________?
A. 0.05
B. 0.10
C. 0.15
D. 0.20
