Multiple choice question for engineering
Set 1
1. Which of the following is not a core machine?
a) Jolt machine
b) Core blower
c) Sand slinger
d) Mill setter
Answer
Answer: d [Reason:] Among the following, mill setter is not any type of a core machine, while the other three are few of the types of core machine.
2. Which cores are made manually in hand filled core boxes?
a) Small sized-mass production
b) Small sized-limited production
c) Large sized-mass production
d) Large sized-limited production
Answer
Answer: b [Reason:] Small sized cores are made manually in the hand filled core boxes. For making large sized products for mass production, these cores cannot be employed.
3. Weak cores are reinforced using what?
a) Iron wires
b) Steel wires
c) Bronze wires
d) Cobalt wires
Answer
Answer: b [Reason:] Weak cores need to be strengthened. And hence, for this purpose, reinforcement is provided, in the form of steel wires.
4. In shell core making, the core box is heated up to what temperature?
a) 400°F – 600°F
b) 500°F – 700°F
c) 600°F – 800°F
d) 800°F – 1000°F
Answer
Answer: a [Reason:] A decent amount of temperature has to be attained for the operation of shell core making. In shell core making, the core box has to be heated to a temperature of almost 400°F – 600°F.
5. The following figure represents what?
a) Strickle core box
b) Gang core box
c) Left and right hand core boxes
d) Loose piece core box
Answer
Answer: c [Reason:] The following figure represents two core boxes, in which one is facing to the right, while the other is facing is towards the left. Hence, it depicts left and right hand core boxes.
6. What does the following figure represent?
a) Half core box
b) Split core box
c) Gang core box
d) Loose piece core box
Answer
Answer: a [Reason:] The following figure represents a half core box. This type of core box is mainly used for the production of cores which are cylindrical in shape.
7. Which core box is represented by the following figure?
a) Half core box
b) Dump core box
c) Split core box
d) Gang core box
Answer
Answer: b [Reason:] The given figure represents a dump core box which is used for making rectangular or trapezoidal cores.
8. What does the following figure represent?
a) Sand slinger
b) Core extrusion machine
c) Pattern and core prints
d) Core blowing machine
Answer
Answer: c [Reason:] The following figure represents pattern and core prints. These core prints make up core seats when they are put into the sand for making mold.
9. A sand slinger works at a high speed.
a) True
b) False
Answer
Answer: a [Reason:] A sand slinger uses a high speed rotating impeller which is used for throwing sand in the core box.
10. Cylindrical cores are made using Dump core boxes?
a) True
b) False
Answer
Answer: b [Reason:] Dump core boxes are helpful in making rectangular or square cores. Cylindrical cores are made using half core boxes.
Set 2
1. With what does iron react to give out Ferrous Oxide?
a) Carbon dioxide
b) Nitrogen
c) Ozone
d) Oxygen
Answer
Answer: d [Reason:] Iron when reacts with Oxygen gas, it produces the compound, ferrous oxide. Ferrous oxide is an inorganic compound, and possesses black colored appearance.
2. What is the chemical formula of fayalite?
a) FeO2SiO2
b) FeOSiO2
c) FeO3SiO2
d) FeO2SiO3
Answer
Answer: b [Reason:] The chemical representation of the compound fayalite is given by FeOSiO2. Fayalite is also known by the name, iron chrysolite.
3. What is the chemical formula of silica?
a) SiO
b) SiO2
c) SiO3
d) SiO4
Answer
Answer: b
4. Silica reacts with what to give out fayalite?
a) Iron
b) Iron Sulphate
c) Iron Oxide
d) Iron Carbide
Answer
Answer: c [Reason:] In the formation of the compound fayalite (FeOSiO2), Iron oxide reacts with silica to give out the compound fayalite or iron chrysolite.
5. What percent of magnesium is used in mold metal reactions?
a) More than 1%
b) More than 2%
c) More than 3%
d) More than 4%
Answer
Answer: a [Reason:] In the mold metal reactions, there is extremely less amount of magnesium used. Approximately more than 1% of magnesium is used in the reactions containing light alloys.
6. Which metal in aluminium alloy reacts with water to give out hydrogen filled pinholes?
a) Manganese
b) Iron
c) Magnesium
d) Aluminium
Answer
Answer: c [Reason:] Magnesium which is present in small quantity inside the light alloy, when reacts with water, causes the formation of hydrogen filled pinholes.
7. What is the condition for mold metal reaction to take place?
a) Radiating contact between gas and metal
b) Direct contact between gas and metal
c) Radiating contact between gas and oxide film
d) Direct contact between gas and oxide film
Answer
Answer: b [Reason:] For mold – metal reaction to take place, the condition is that, there has to be a direct contact between the gas and the metal.
8. How can the pinholes be reduced?
a) Oxidizing
b) Deoxidizing
c) Adding ozone
d) Adding calcium carbonate
Answer
Answer: b [Reason:] When pinholes are being produced more than necessary, the metal-mold reaction has to be deoxidized, which can cause the pinholes to reduce.
9. What is differential freezing?
a) Increase in oxygen concentration
b) Increase in nitrogen concentration
c) Increase in carbon concentration
d) Increase in hydrogen concentration
Answer
Answer: d [Reason:] When there is an increase in the hydrogen concentration of the metal – mold reaction, then that phenomena is called as differential freezing.
10. In light alloys, metal – mold reaction can be suppressed by adding Helium.
a) True
b) False
Answer
Answer: b [Reason:] In light alloy, metal – bond reaction can be suppressed, but not by using Helium, but by using Boric acid and ammonium bi-fluoride.
Set 3
1. Which of the following is not a process of ramming?
a) Squeezing
b) Quenching
c) Jolting
d) Slinging
Answer
Answer: b [Reason:] Ramming of sands is considered to be one of the most important operations of molding machines. Ramming is done in a molding box. A few types of ramming operations are, squeezing, jolting, slinging and blowing.
2. Which machine is most useful for making shallow patterns?
a) Squeeze machine
b) Sand slinger
c) Jolt-squeeze machine
d) Jot-squeeze roll over
Answer
Answer: a [Reason:] In a squeeze machine, there is a squeezer head or a plate which is used as pressing board to force the sand inside or compress it. This machine, is mostly used for shallow patterns.
3. Which of the following is not a power operated molding machine?
a) Squeeze machine
b) Sand slinger
c) Jolt-squeeze machine
d) Jot-sand machine
Answer
Answer: d [Reason:] In power operated molding machines, there is a use of compressed air and hydraulic machinery. There are also electromagnets used in it. These machines are classified as, squeeze machine, sand slinger, jolt-squeeze machine and sand slinger.
4. At what pressure, does the compressed air enter in squeezing machine?
a) 6 kg(f)/cm2
b) 7 kg(f) /cm2
c) 8 kg(f) /cm2
d) 9 kg(f) /cm2
Answer
Answer: b [Reason:] In squeezing machines, the sand used is rammed very hard. It has a greater density at the surface than at the interiors. The air required for compression of the sand, enters at 7 kg(f) /cm2.
5. Up to what depth of molds is a squeezing machine used?
a) 10 cm
b) 12 cm
c) 15 cm
d) 18 cm
Answer
Answer: c [Reason:] It is considered among one of the limitations of squeezing molding machines, that they can only be used if the mold is shallow. The depth up to which a squeezing molding machine can be used is 15 cm.
6. With an increase in the diameter of the piston, how does the molding force change?
a) Increases
b) Decreases
c) Does not change
d) Not related
Answer
Answer: a [Reason:] The force needed for molding is directly related to the square of the diameter of the piston, that is, with an increase in the diameter of the piston, there will be an increase in the molding force.
7. With a decrease in the length of the jolt stroke, how will the power of jointing be affected?
a) Increases
b) Decreases
c) No affect
d) Entities not related
Answer
Answer: b [Reason:] In a jolting machine, a cylinder and piston mechanism is present. The power of jolting is directly linked the length of the jolt stroke, which means, with a decrease in the length of jolt stroke, there would be a decrease in the jointing power.
8. With an increase in the jolted area, how does it affect the jolted length?
a) Increases
b) Decreases
c) No change
d) Not related
Answer
Answer: b [Reason:] According to the formula of power required for jolting, the jolted area is inversely related to the length of the jolt stroke, that is, with an increase in the jolt stroke, there will be a decrease in the jolted area and vice versa.
9. Hand molding is an inexpensive process.
a) True
b) False
Answer
Answer: a [Reason:] Hand molding operation need a lot of time for completion and labor effort, but, in case of molding machines, the equipments needed are costly, making the overall process an expensive one.
10. High amount of tapering allowance is required when molding machines are used.
a) True
b) False
Answer
Answer: b [Reason:] In other types of castings, a tapering allowance of at least 3o to 10o is required to be given. But, when the entire process gets mechanized, the tapering allowance can be reduced, and much allowance is not required.
11. In the following squeezing machine apparatus, what does the question mark represent?
a) Diaphragm
b) Plate
c) Pattern
d) Flask
Answer
Answer: c [Reason:] In squeezing machines, the operations are made to happen under some amount of pressure. In this figure, the pattern is kept with the sand beneath it. This pattern therefore will experience the upward force.
12. In the following squeezing machine apparatus, what does the question mark represent?
a) Flask
b) Pattern
c) Pressure column
d) Plate
Answer
Answer: a [Reason:] In a squeezing operation mechanism, there is some amount of sand in the apparatus which is pressurized. This sand is accumulated and not allowed to spread away with the help of the flasks situated at the ends.
13. What is the minimum pressure required to be given in a squeezing process?
a) 4 kg(f)/cm2
b) 5 kg(f)/cm2
c) 6 kg(f)/cm2
d) 7 kg(f)/cm2
Answer
Answer: c [Reason:] In squeezing processes, there is piston used which applies a thrusting force over the sand beneath it. There is air present which gets pressurized in the system. This air pressure, minimum has to be 6 kg(f)/cm2.
14. In the following squeezing machine apparatus, what does the question mark represent?
a) Plate
b) Air column
c) Diaphragm
d) Pattern
Answer
Answer: a [Reason:] In this figure, the question mark represents the plate. In the squeezing process mechanism, there is a plate involved for taking the load from the piston and transferring it on to the sand and air present there.
15. What is the maximum pressure required to be given in a squeezing process?
a) 6.5 kg(f)/cm2
b) 7.5 kg(f)/cm2
c) 8.5 kg(f)/cm2
d) 9.5 kg(f)/cm2
Answer
Answer: b [Reason:] A molding force is applied with the help of a piston in squeezing machines. This causes the air to get pressurized. This minimum pressure of the air can be 6 kg(f)/cm2 and the maximum air pressure can be 7.5 kg(f)/cm2.
Set 4
1. In green sand moulding of steel casting, what is the bentonite percentage composition?
a) 1.5%
b) 2.5%
c) 3.5%
d) 4.5%
Answer
Answer: c [Reason:] In green sand mouldings of steel castings, the dextrin percentage is quite lower, it is around 0.5%. The bentonite percentage composition in green sand molding is calculated to be 3.5%.
2. In green sand moulding of steel casting, what is the dextrine percentage composition?
a) 0.5%
b) 1.5%
c) 2.5%
d) 3.5%
Answer
Answer: a [Reason:] In green sand mouldings of steel castings, the dextrine percentage composition is calculated to be 0.5% and the bentonite percentage in the same green sand is higher than dextrin by around 3%.
3. In green sand moulding of steel casting, what is the moisture percentage composition?
a) 1% – 2%
b) 2% – 3%
c) 3% -4%
d) 4% – 5%
Answer
Answer: c [Reason:] In green sand mouldings of steel castings, the moisture percentage composition is calculated to be 3%- 4% and the amount of bentonite present in the same green sand is around 3.5%.
4. In dry sand moulding of steel casting, what is the bentonite percentage composition?
a) 1%
b) 2%
c) 4%
d) 5%
Answer
Answer: d [Reason:] In dry sand mouldings of steel castings, the bentonite percentage composition is calculated to be 5% and in green sand, the bentonite percentage is calculated to be 3.5%.
5. In dry sand moulding of steel casting, what is the dextrine percentage composition?
a) 0.5%
b) 1.5%
c) 2.5%
d) 3.5%
Answer
Answer: a [Reason:] In dry sand mouldings of steel castings, the dextrine percentage composition is calculated to be 0.5%. In green sands, the dextrin content is also 0.5%, which is in green sand and in dry sand, the percentage of dextrine is same.
6. In green sand moulding of steel casting, what is the moisture percentage composition?
a) 2-3%
b) 3-4%
c) 4-5%
d) 5-6%
Answer
Answer: d [Reason:] In dry sand mouldings of steel castings, the moisture percentage composition is calculated to be 5-6%. In green sands, the moisture content is relatively lower than dry sands. It is around 3% to 4%.
7. In synthetic sands of aluminium alloys, what is the bentonite percentage composition?
a) 2-5%
b) 3-5%
c) 4-5%
d) 5-6%
Answer
Answer: c [Reason:] In synthetic sands of aluminium alloys, the bentonite percentage composition is calculated to be 4-5%. Whereas, in the case of green sands, the bentonite percentage is recorded to be around 3.5%.
8. In gray iron castings of facing sand mixtures, what is the bentonite percentage composition?
a) 2-3%
b) 3-4%
c) 4-5%
d) 5-6%
Answer
Answer: a [Reason:] In gray cast irons of facing sand mixtures, the bentonite percentage composition is calculated to be 2-3%. Whereas, in the case of green sands, the bentonite percentage is recorded to be around 3.5%.
9. In magnesium alloys, what is the bentonite percentage composition?
a) 1%
b) 2%
c) 3%
d) 4%
Answer
Answer: d [Reason:] In magnesium alloys, the bentonite percentage composition is calculated to be 4%. Whereas, in the case of green sands, the bentonite percentage is recorded to be around 3.5%.
10. In magnesium alloys, the water content in percentage is 10%.
a) True
b) False
Answer
Answer: b [Reason:] In magnesium alloys, the water content in terms of percentage is not 10%. The amount of water in terms of percentage composition is much lower than that. The composition of water around 2%.
Set 5
1. In sand preparation, which of the following is not used as an additive?
a) Clay
b) Cereal
c) Wax
d) Moisture
Answer
Answer: c [Reason:] Among the following, clay and cereals are binders, hence used. Moisture too is needed for sand preparation, but in case of wax, it is not counted among additives.
2. Which of the following process deals with the amount of moisture to be added?
a) Sand mixing
b) Sand preparation
c) Sand conditioning
d) Sand tempering
Answer
Answer: d [Reason:] Sand tempering is linked with sand preparation, wherein the amount of moisture needed as an additive is added.
3. Which of the following process deals with preparation the mold sand?
a) Sand mixing
b) Sand preparation
c) Sand tempering
d) Sand conditioning
Answer
Answer: d [Reason:] Among sand mixing, sand preparation, sand tempering and sand conditioning, the process that deals with preparation of the mold sand is sand conditioning.
4. Which of the following process deals with mixing the molding sand elements?
a) Sand mixing
b) Sand preparation
c) Sand tempering
d) Sand conditioning
Answer
Answer: b [Reason:] In sand preparation, the process which is dealing with the basic preparation of mold sand is called as sand conditioning. The mixing of molding elements of sand is dealt by the process called sand preparation.
5. What is the temperature requirement of sand, for manufacturing?
a) Below 40°C
b) Below 50°C
c) Below 60°C
d) Below 70°C
Answer
Answer: a [Reason:] Among the basic conditions of sand, temperature condition is considered an essential factor. The temperature requirement of sand used for manufacturing should be below 40°C.
6. To avoid difficulties in making of molds, sand should be cooled below what temperature?
a) 100°F
b) 120°F
c) 140°F
d) 160°F
Answer
Answer: a [Reason:] In sand preparation, the requirement of temperature for production is less than 40°C. The said sand, being used for manufacturing, should be cooled down below 100°F to avoid later difficulties in making the molds.
7. What should be the accuracy of automatic moisture control for manufacturing sands?
a) ± 0.1%
b) ± 0.2%
c) ± 0.3%
d) ± 0.4%
Answer
Answer: a [Reason:] In any system, the accuracy in its working is considered to be one of the most essential feature of that process. The accuracy of automatic moisture control for manufacturing sand must be ± 0.1%.
8. A low speed muller is used in mechanized foundries.
a) True
b) False
Answer
Answer: b [Reason:] In mechanized foundries, a high speed muller is essentially used which rotates in horizontal direction.
9. How much time is taken by sand, for sand preparation in terms of muller time?
a) 33 to 50 percent of muller time
b) 14 to 29 percent of muller time
c) 25 to 40 percent of muller time
d) 46 to 62 percent of muller time
Answer
Answer: a [Reason:] Muller time is the time needed for the high speed muller to complete its function. For sand preparation, approximately 33 to 50 percent of muller time is needed.
10. Air blasts are provided for forced cooling of sand after muller operation.
a) True
b) False
Answer
Answer: a [Reason:] Mullers usually need approximately 33 to 50 percent of mulling time. In a high speed sand preparation unit, after the muller operation is complete, to cool the sand, air blasts are used.