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1) Investment material used for cobalt-chromium alloys is_____________? a. Gypsum bonded b. Phosphate bonded c. Silica bonded d. None of the above
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2) Silica sol__________________? a. Is applied to the walls of the investment to produce hygroscopic expansion b. Increase the strength and the setting expansion of the phosphate-bonded investment c. Acts as a retarder in the silica bonded investments d. Acts as a refractory in the Silica bonded investments
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3) Boxing wax is also called as________________? a. Carding wax b. Inlay wax c. Utility wax d. Sticky wax
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4) Shape memory in NiTi is because of stress induced form__________________? a. Austenite to martensite b. Martensite to austenite c. Ferrite to austenite d. Austenite to ferrite
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5) Casting shrinkage is compensated by_______________? a. Thermal expansion b. Hygroscopic expansion c. Wax expansion d. All of the above
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6) The gold alloys used for casting contain at least…. percent of precious metal according to ADA specification number 5________________? a. 55 b. 65 c. 75 d. 85
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7) Impurities in casting is removed by________________? a. Annealing b. Degassing c. Pickling d. Conditioning
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8) Shape memory is seen in________________? a. Stainless steel wire b. NITTINOL wire c. TMA wire d. Aluminium
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9) The best pickling solution for gypsum bonded investment is_______________? a. Hydrochloric acid b. Nitric acid c. Sulphuric acid d. Phosphoric acid
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10) Corrosion of stainless steel is due to formulation of_________________? a. Chromium carbide b. Carbon carbide c. Iron carbide d. Nickel carbide
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11) The rapid decrease in tensile strength and increase in ductility of a wrought metal is seen in which stage of annealing ? a. Recovery stage b. Recrystallisation stage c. Grain growth stage d. All of the above
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12) Which one of the following categories of dental materials has the highest thermal conductivity_________________? a. Unfilled acrylic plastics b. Gold alloys c. Porcelains d. Zinc phosphate cements
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13) Most biocompatible material in oral cavity is_______________? a. Platinium b. Palladium c. Titanium d. Gold
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14) Which of the waxes are derived from the lignite_________________? a. Paraffin wax b. Inlay wax c. Microcrystalline wax d. Montan wax
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15) Silver plated dyes use an electrolytic bath of_______________? a. Silver fluorides b. Silver cyanide c. Silver bromide d. Silver iodide
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16) Suck back porosity is due to_________________? a. Attached impurities on undersurface of casting b. Hot spot c. No rapid cooling d. Inadequate melting temperature
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17) Air bubbles formed on the surface of casting is probably due to________________? a. Improper casting pressure b. Improper heating of the investment c. Improper angulation of sprue d. Improper wetting of the wax pattern by the investment
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18) Asbestos liner is used in a casting ring to________________? a. Facilitate venting of the mold b. Retard the heating of the investment c. Permit expansion of the world d. All of the above
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19) Which of the following decrease with strain hardening______________? a. Surface hardness b. Strength c. Proportion limit d. Corrosion resistance
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20) Suck back porosity in the casting can be eliminated by________________? a. Increasing the mould metal temperature difference b. Increasing the flow of molten metal c. Flaring the point of the sprue attachment d. All of the above
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21) The component in very minor quantity in stainless steel that changes the properties to a maximum level is____________? a. Carbon b. Molybdenum c. Chromium d. Nickel
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22) Binder used in Gypsum investment is_________________? a. Silica b. Quartz c. Cristobolite d. Calcium sulphate monohydrate
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23) Nickel-Titanium alloy has__________________? a. Unreliable spring back b. low spring back c. Minimal spring back d. None of the above
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24) Advantage of titanium over other base metal alloys_______________? a. Low weight b. Low cost c. Low strength d. Low melting point
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25) Component of inlay wax which makes it flake resistant is_____________? a. Paraffin b. Carnauba c. Gum dammar d. Canadelila
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26) Microstructure of cobalt chromium alloy in cast condition is______________? a. Fibrous b. Homogeneous c. Inhomogenous d. amorphous
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27) Dendrites in cst alloys form by mechanism of_________________? a. Constitutional superconductivity b. Constitutional supercooling c. Constitutional supergriting d. Constitutional supergraining
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28) Compared with noble metals, base metals show_______________? a. Increased hardness b. Increased ductility c. Better biocompatibility d. Increased density
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29) Mechanical properties of Cp Titanium are similar to alloys_____________? a. Type III and Type IV gold b. Type V and type VI gold c. Type VII and type VIII gold d. None of the above
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30) The effects associated with cold working can be eliminated by a heat treatment called______________? a. Age hardening heat treatment b. Annealing heat treatment c. Homogenization heat treatment d. Solution heat treatment
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31) With indirect spruing. Which one of the following porosities can be minimised_______________? a. Back pressure porosity b. Localized shrinkage porosity c. Pin hole porosity d. Micro porosity
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32) The linear solidification shrinkage of Type IV Ni-Cr based alloys is_______________? a. 2.3% b. 1.56% c. 1.37% d. 3%
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33) Which of the following cast gold alloys is used for fabricating partial denture frameworks______________? a. Type I – Soft b. Type II – Hard c. Type III – Hard d. Type IV – Extra Hard
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34) Modern dental noble metal casting alloys generally have equiaxed fine grain structures because of the incorporation of small amounts of______________? a. Chromium b. Indium c. Irridium d. Palladium
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35) Nickel is added to wrought gold alloys as______________? a. Strengtherner b. Hardener c. Whitens the alloy d. Scavenger
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36) Stages of annealing in order_________________? a. Recovery recrystallization grain growth b. Recrystallization recovery, grain growth c. Grain Growth Recrystallization recovery d. Melting point, grain growth, Recrystallization
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37) The term ordered hardening heat treatment used in which of the following dental alloys ? a. Gold-Copper b. Nickel-Chromium c. Nickel-Titanium d. Silver-Palladium
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38) Linear coefficient of thermal expansion of metal used for metal caramic restoration range from________________? a. 11.5-12.5×10-6/°C b. 10.5-11.5×10-6/°C c. 13.5-14.5×10-6/°C d. 16.5-17.5×10-6/°C
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39) 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
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40) Annealing is also known as_______________? a. Soft hardening treatment b. Hard hardening treatment c. Precipitating heat treatment d. Stress relieving heat treatment
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