Gypsum Products MCQs

Option A: Rapid spatulation results in decreased setting time

Option B: 2% potassium sulphate is accelerator

Option C: Citrates are retarders

Option D: All of the above

Correct Answer: All of the above ✔

Option A: Not waiting for 20 min before pouring

Option B: High speed accelerator

Option C: Air incorporation in the mix

Option D: All of the above

Correct Answer: All of the above ✔

Option A: Increased spatulation

Option B: Adding potassium sulfate

Option C: Less water powder ratio

Option D: Allowing setting under water

Correct Answer: Adding potassium sulfate ✔

Option A: Na2 So4

Option B: Nacl

Option C: Citrales

Option D: K2 So4

Correct Answer: Citrales ✔

Option A: Impression plaster

Option B: Model plaster

Option C: Stone plaster

Option D: Die stone

Correct Answer: Die stone ✔

Option A: Testing the strength of plaster of paris

Option B: Evaluating the setting time of plaster of pris

Option C: Testing the metal hardness

Option D: Testing the purity of noble metals

Correct Answer: Evaluating the setting time of plaster of pris ✔

Option A: Difference in solubility of CaSo4 ½ H2O + CaSO4+ 2H2O

Option B: Reaction between CaSO4+ 2H2O and water

Option C: Nucleation and growth of CaSo4 ½ H2O crystals

Option D: Reaction between hemihydrate and hihydrate

Correct Answer: Difference in solubility of CaSo4 ½ H2O + CaSO4+ 2H2O ✔

Option A: Impression plaster

Option B: Class I stone / Hydrocal

Option C: Class II stone/Densite

Option D: Model plaster

Correct Answer: Impression plaster ✔

Option A: Is wet calcined hemihydrate

Option B: Has porous and irregular crystals

Option C: Is a – hamihydrate

Option D: Has a W / P of 0.2

Correct Answer: Has porous and irregular crystals ✔

Option A: 0.05

Option B: 0.10

Option C: 0.15

Option D: 0.20

Correct Answer: 0.10 ✔

Option A: Chemical composition

Option B: Self life

Option C: Sharpe and size of particles

Option D: Solubility in water

Correct Answer: Sharpe and size of particles ✔

Option A: Impressions

Option B: Casts

Option C: Die

Option D: Casts and Dies

Correct Answer: Casts ✔

Option A: Dry strength

Option B: Green strength

Option C: Water strength

Option D: Compressive strength

Correct Answer: Green strength ✔

Option A: Which undergoes rapid expansion

Option B: In which accelerators or retarders have been added according to need

Option C: In which amount of water of hydration is controlled

Option D: In which the crystals are all of uniform size

Correct Answer: In which accelerators or retarders have been added according to need ✔

Option A: Plaster of paris

Option B: Soluble plaster

Option C: Anti – expansion solution

Option D: Die stones

Correct Answer: Soluble plaster ✔

Option A: Solubility

Option B: Shelf life

Option C: Chemical formula

Option D: Particle porosity

Correct Answer: Particle porosity ✔

Option A: More water

Option B: Less water

Option C: no water

Option D: None of the above

Correct Answer: More water ✔

Option A: Class II stone

Option B: Densite

Option C: Class I stone or hydrocal

Option D: Model or lab plaster

Correct Answer: Class I stone or hydrocal ✔

Option A: Alpha – hemihydrates

Option B: Beta – hemihydrates

Option C: Calcium sulphate dihydrate

Option D: Orthorhombic anhydrate

Correct Answer: A. Alpha – hemihydrates ✔

Option A: Tensile strength

Option B: Wet strength

Option C: Green strength

Option D: compressive strength

Correct Answer: compressive strength ✔

Option A: To regulate the setting expansion

Option B: Regulate setting time

Option C: Acts as retarder

Option D: None

Correct Answer: Regulate setting time ✔

Option A: Slower the hygroscopic expansion

Option B: Greater the hygroscopic expansion

Option C: Normal setting expansion

Option D: No setting expansion

Correct Answer: Greater the hygroscopic expansion ✔

Option A: 1

Option B: 4

Option C: 12

Option D: 25

Correct Answer: 25 ✔

Option A: Modify setting time

Option B: Modify setting expansion

Option C: Modify strength

Option D: Decrease the porosity

Correct Answer: Modify setting time ✔

Option A: H2O interferes with hygroscopic expansion

Option B: H2O inhibits polymerization of dental resin

Option C: H2O interferes with Crystallization of dihydrate

Option D: Gypsum is slightly soluble in water and the surface of the cast will be eroded

Correct Answer: Gypsum is slightly soluble in water and the surface of the cast will be eroded ✔

Option A: They are more regular in shape and dense

Option B: They are more regular in shape and highly porous

Option C: They are more irregular in shape and porous

Option D: They are more dense and prismatic in shape

Correct Answer: They are more irregular in shape and porous ✔

Option A: Altering P / L Ratio

Option B: Altering temperature of mixing water

Option C: Speed and length of hand spatulation

Option D: Addition of accelerators and retarders

Correct Answer: Addition of accelerators and retarders ✔

Option A: Stone

Option B: Plaster

Option C: Investment

Option D: All of the above

Correct Answer: All of the above ✔

Option A: Sodium fluoride

Option B: Potassium fluoride

Option C: Potassium sulfate

Option D: Aluminium sulfate

Correct Answer: Potassium sulfate ✔

Option A: Investment

Option B: Hydrocolloids

Option C: Amalgam

Option D: Silicate

Correct Answer: Investment ✔

Option A: Setting time

Option B: Setting expansion

Option C: Hardness of the set product

Option D: None of the above

Correct Answer: Setting time ✔

Option A: Calcium sulphate hemihydrate

Option B: Calcium phosphate

Option C: Calcium anhydrate

Option D: Calcium sulphate dihydrate

Correct Answer: Calcium sulphate hemihydrate ✔

Option A: Impression of single tooth

Option B: Impression of whole teeth

Option C: Replica of single tooth

Option D: Replica of whole teeth

Correct Answer: Replica of single tooth ✔

Option A: Plastic bowl

Option B: Rubber bowl

Option C: Glass bowl

Option D: Metal bowl

Correct Answer: Rubber bowl ✔

Option A: 18.6ml

Option B: 22.2ml

Option C: 30.4ml

Option D: 45.3ml

Correct Answer: 18.6ml ✔

Option A: Dry strength

Option B: Compressive strength

Option C: Strength of dental stone due to green colour

Option D: The wet strength

Correct Answer: The wet strength ✔

Option A: 0.28 and 0.6

Option B: 0.6 and 0.28

Option C: 0.6 and 3.2

Option D: 0.28 and 0.98

Correct Answer: 0.28 and 0.6 ✔

Option A: CaO

Option B: CaCO3

Option C: (CaSO4)2-½H2O

Option D: CaSO4-2H2O

Correct Answer: (CaSO4)2-½H2O ✔