Plaster mix____________? A. Rapid spatulation results in decreased setting time B. 2% potassium sulphate is accelerator C. Citrates are retardersD. All of the above

A rough / Chalky surface of the cast is due to_______________? A. Not waiting for 20 min before pouring B. High speed accelerator C. Air incorporation in the mixD. All of the above

The setting expansion of gypsum products can be reduced by________________? A. Increased spatulationB. Adding potassium sulfate C. Less water powder ratio D. Allowing setting under water

Most commonly used retarder in gypsum_____________? A. Na2 So4 B. NaclC. Citrales D. K2 So4

Gypsum product having least expansion_____________? A. Impression plaster B. Model plaster C. Stone plasterD. Die stone

Gillmore needle is used for_______________? A. Testing the strength of plaster of parisB. Evaluating the setting time of plaster of pris C. Testing the metal hardness D. Testing the purity of noble metals

Setting of POP is result of______________? A. Difference in solubility of CaSo4 ½ H2O + CaSO4+ 2H2O B. Reaction between CaSO4+ 2H2O and water C. Nucleation and growth of CaSo4 ½ H2O crystals D. Reaction between hemihydrate and hihydrate

Type I gypsum product is also called_______________? A. Impression plaster B. Class I stone / Hydrocal C. Class II stone/Densite D. Model plaster

Plaster of paris _____________? A. Is wet calcined hemihydrateB. Has porous and irregular crystals C. Is a – hamihydrate D. Has a W / P of 0.2

As per DNA No. 25, minimum amount of setting expansion required for type V gypsum products_______________? A. 0.05B. 0.10 C. 0.15 D. 0.20