Objective Type Questions on Metal Casting
1- The sprue should be attached to the wax pattern
(A) On a flat surface
(B) At the thinnest point
(C) At the point of greatest bulk
(D) At any proximal surface
2- Flux is used during casting to
(A) Remove the oxides formed on the gold alloy
(B) Lower the melting point
(C) Replace casting wax
(D) Speed the burnout process
3- The wax pattern should be invested immediately to decrease the dimensional changes caused by
(A) Decrease of flow
(B) Continuous expansion
(C) Water loss
(D) Relaxation of internal stresses
4- The best material for duplication of cast is
(A) Alginate
(B) Agar agar
(C) Polysulfide
(D) Plaster of Paris
5- During casting procedure, subsurface porosity can be controlled by
(A) Mold temperature
(B) Sprue length
(C) Rate at which the molten metal enters the mold
(D) Melt temperature
6- Which of the following zones is used for melting alloys during casting?
(A) Oxidizing flame
(B) Reducing flame
(C) Green flame
(D) All of the above
7- Impurities in casting are removed by
(A) Annealing
(B) Degassing
(C) Pickling
(D) Conditioning
8- Fins and spines on the casting are seen due to
(A) Prolonged heating
(B) Rapid heating
(C) Under heating
(D) High pressure during casting
9- Titanium casting is done
(A) Under vacuum in argon atmosphere
(B) Under air pressure in nitrogen atmosphere
(C) Under air pressure in vanadium atmosphere
(D) None of the above
10- Binder in the investment materials is:
(A) Gypsum
(B) Quartz
(C) Silica
(D) Water
11- Singles crystal turbine blades of nickel-based superalloys for aero-engines are manufactured using
(A) Investment casting
(B) Die Casting
(C) Squeeze casting
(D) Directional Solidification
12- Wax pattern is used in
(A) shell moulding
(B) die casting
(C) centrifugal casting
(D) investment casting
13- The process by which shell like casting (like toys) are made is
(A) shell moulding
(B) centrifugal casting
(C) slush casting
(D) die casting
14- For casting of intricate shape turbine blades made of high strength alloys, the most suitable process is
(A) die casting
(B) investment casting
(C) slush casting
(D) centrifugal casting
15- For feeding the liquid molten metal into the mould, converging passage is used
(A) to increase the rate of feeding
(B) to reduce the wastage of cast metal
(C) to reduce air aspiration
(D) to easily break off the protruding portion of casting
16- The purpose of adding wood flour or saw dust to foundry sand is to improve
(A) Mouldability
(B) Collapsibility
(C) Dry strength
(D) Hot strength
17- Investment casting uses pattern made of …….
(A) Wax
(B) Clay
(C) Metal
(D) Wood
18- Casting defect development due to inadequate venting is
(A) Inclusions
(B) Cold Shuts
(C) Blow holes
(D) None of the options
19- Misrun is a casting defect which occurs due to
(A) Very high pouring temperature of the metal
(B) Insufficient fluidity of the molten metal
(C) Absorption of gases by the liquid metal
(D) Improper alignment of the mould flasks
20- The passage way of bringing the molten to the mould cavity is called as
(A) piping system
(B) entry system
(C) gating system
(D) loaming system
ANSWERS:
1-(C), 2-(A), 3-(D), 4-(B), 5-(C), 6-(B), 7-(C), 8-(B), 9-(A), 10-(B), 11-(D), 12-(D), 13-(C), 14-(B), 15-(C), 16-(B), 17-(A), 18-(C), 19-(B), 20-(C)