Question: Plaster of paris _____________?

• 1. Is wet calcined hemihydrate
• 2. Has porous and irregular crystals
• 3. Is a – hamihydrate
• 4. Has a W / P of 0.2

Question: As per DNA No. 25, minimum amount of setting expansion required for type V gypsum products_______________?

• 1. 0.05
• 2. 0.10
• 3. 0.15
• 4. 0.20

Question: The main difference between dental stone and dental plaster is______________?

• 1. Chemical composition
• 2. Self life
• 3. Sharpe and size of particles
• 4. Solubility in water

Question: Gypsum is used for________________?

• 1. Impressions
• 2. Casts
• 3. Die
• 4. Casts and Dies

Question: 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____________?

• 1. Dry strength
• 2. Green strength
• 3. Water strength
• 4. Compressive strength

Question: Balanced stone is dental stone_______________?

• 1. Which undergoes rapid expansion
• 2. In which accelerators or retarders have been added according to need
• 3. In which amount of water of hydration is controlled
• 4. In which the crystals are all of uniform size

Question: Impression plaster containing potato starch is called______________?

• 1. Plaster of paris
• 2. Soluble plaster
• 3. Anti – expansion solution
• 4. Die stones

Question: Powders of dental plaster and dental stone differ mainly in____________?

• 1. Solubility
• 2. Shelf life
• 3. Chemical formula
• 4. Particle porosity

Question: Beta hemihydrate particles absorb______________?

• 1. More water
• 2. Less water
• 3. no water
• 4. None of the above

Question: Type III Dental gypsum is__________________?

• 1. Class II stone
• 2. Densite
• 3. Class I stone or hydrocal
• 4. Model or lab plaster