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Gypsum product 2

Total questions: 10

Worksheet time: 5mins

Name
Class
Date
1.

The function of 2% potassium sulphate in a gypsum product is_____________?

a)

To regulate the setting expansion

b)

Regulate setting time

c)

Acts as retarder

d)

None

2.

Finer particle size of silica______________?

a)

Slower the hygroscopic expansion

b)

Greater the hygroscopic expansion

c)

Normal setting expansion

d)

No setting expansion

3.

Placing cast under tap water is to be avoided as______________?

a)

H2O interferes with hygroscopic expansion

b)

H2O inhibits polymerization of dental resin

c)

H2O interferes with Crystallization of dihydrate

d)

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

4.

The β (Beta) hemihydrate of gypsum requires more water to float its powder particles because______________?

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

5.

Which is gypsum product_______________?

a)

Stone

b)

Plaster

c)

Investment

d)

All of the above

6.

The most commonly used accelerator in gypsum product is___________________?

a)

Sodium fluoride

b)

Potassium fluoride

c)

Potassium sulfate

d)

Aluminium sulfate

7.

The hygroscopic technique is associated with______________?

a)

Investment

b)

Hydrocolloids

c)

Amalgam

d)

Silicate

8.

Die is________________?

a)

Impression of single tooth

b)

Impression of whole teeth

c)

Replica of single tooth

d)

Replica of whole teeth

9.

Water of reaction needed to react completely with 100 g of calcium sulphate hemihydrates to convert it to calcium sulphate dihydrate______________?0

a)

18.6 ml

b)

22.2ml

c)

30.4ml

d)

45.3ml

10.

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