Metallurgy MCQs

Option A: To strength amalgam

Option B: In orthodontic wires

Option C: To construct clasps for partial dentures

Option D: To replace internal gold restorations

Correct Answer: In orthodontic wires ✔

Option A: Animal

Option B: Mineral

Option C: Insect

Option D: Vegetable

Correct Answer: Animal ✔

Option A: Utility wax

Option B: Base plate wax

Option C: Beading wax

Option D: Boxing wax

Correct Answer: Utility wax ✔

Option A: Pinhole porosity

Option B: Gas inclusion porosity

Option C: Micro porosity

Option D: Subsurface porosity

Correct Answer: Subsurface porosity ✔

Option A: To provide a smooth and glossy surface

Option B: Increase toughness

Option C: Decrease toughness

Option D: Decrease flow at room temperature

Correct Answer: Decrease flow at room temperature ✔

Option A: Platinum

Option B: Copper

Option C: Silver

Option D: Gold

Correct Answer: Copper ✔

Option A: Tensile strength

Option B: Proportional limit

Option C: Ductility

Option D: Hardness

Correct Answer: Ductility ✔

Option A: Form an opening of molten metal to enter the mold

Option B: Help polish cast restorations

Option C: Eliminate air bubbles on the wax pattern

Option D: Reproduce fine detail

Correct Answer: Form an opening of molten metal to enter the mold ✔

Option A: Carbon

Option B: Chromium

Option C: Nickel

Option D: Titanium

Correct Answer: Titanium ✔

Option A: 100 Mpa

Option B: 240 Mpa

Option C: 560 Mpa

Option D: 700 Mpa

Correct Answer: 560 Mpa ✔

Option A: Dimensional change

Option B: Thermal conductivity

Option C: Warpage

Option D: Tarnish and corrosion

Correct Answer: Tarnish and corrosion ✔

Option A: Impurities in gold

Option B: Improper venting

Option C: A and B

Option D: None of the above

Correct Answer: None of the above ✔

Option A: High gold

Option B: Low gold

Option C: Palladium – Ag

Option D: Ni – Cr

Correct Answer: D. Ni – Cr ✔

Option A: Improve bonding

Option B: Harden the metal ceramic Ag-Pd alloy

Option C: Both A and B

Option D: None of the above

Correct Answer: Both A and B ✔

Option A: Iowa wax

Option B: Modeling wax

Option C: Green stick wax

Option D: None of the above

Correct Answer: Iowa wax ✔

Option A: More porous investment in the mould

Option B: Narrow sprue diameter

Option C: Hollow sprue pin

Option D: Large reservoir

Correct Answer: Narrow sprue diameter ✔

Option A: Shrinkage of alloy on cooling

Option B: Investment breakdown

Option C: Incomplete wax elimination

Option D: Incomplete gas elimination

Correct Answer: Incomplete wax elimination ✔

Option A: 700°C

Option B: 1,300°C

Option C: 1,063°C

Option D: 900°C

Correct Answer: 700°C ✔

Option A: 30% cobalt and 60% chrominum

Option B: 60% cobalt and 30% chrominum

Option C: 1% palladium

Option D: 20% gold

Correct Answer: 60% cobalt and 30% chrominum ✔

Option A: Ti 6Al 4V

Option B: Ti 5Al 4V

Option C: Ti 5Al 5V

Option D: Ti 6Al 6V

Correct Answer: Ti 6Al 4V ✔

Option A: Decrease flow

Option B: Continuous expansion

Option C: Relaxation of the internal stresses

Option D: Water loss

Correct Answer: Relaxation of the internal stresses ✔

Option A: 19%

Option B: 2%

Option C: 1.7%

Option D: 4%

Correct Answer: 1.7% ✔

Option A: Remove the oxides formed on the gold alloy

Option B: Lower the melting point

Option C: Replace casting wax

Option D: Speed the burnout process

Correct Answer: Remove the oxides formed on the gold alloy ✔

Option A: High quality iron

Option B: Chrome

Option C: Cobalt

Option D: Nickel

Correct Answer: Chrome ✔

Option A: Ease of construction of denture

Option B: Preserving the sulci

Option C: Ease of pouring an impression

Option D: All of the above

Correct Answer: Ease of pouring an impression ✔

Option A: ¼ inch

Option B: ½ inch

Option C: 3/8 inch

Option D: one inch

Correct Answer: ¼ inch ✔

Option A: Decrease its strength and ability to be hardened

Option B: Decrease its tarnish resistance

Option C: Increase its fusion temperature

Option D: Redden the alloy

Correct Answer: Increase its fusion temperature ✔

Option A: They have a modulus of elasticity twice that of gold alloys

Option B: They are more rigid than gold alloys

Option C: They have higher ductility than gold alloys

Option D: They have a lower proportional limit than gold alloys

Correct Answer: They have higher ductility than gold alloys ✔