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Correct OPTION is (B) False

Easiest explanation: After ramming of sand, the core box is put on a core PLATE SUPPORTED by the machine bed. A rapping ACTION is generated on the core box by vibrating a vertical plate. This rapping action helps in extracting the core from the core box. After rapping the core box, the core is pulled up and gets onto the core plate.

Correct option is (a) Plate

Explanation: 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.

The correct option is (a) True

The best I can explain: Dust CONTENT of the air is GENERALLY kept low in some modern foundries, thus reducing the hazards to the WORKERS. In sand moulding, the sand might get into the bearings of a roller conveyor or the moving parts of MACHINES. Many foundry machines breakdowns due to the presence of sand or dust in the air.

The correct choice is (c) Pattern

Easiest explanation: 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.

The CORRECT answer is (a) Squeeze MACHINE

Easiest EXPLANATION: In a squeeze machine, there is a squeezer HEAD or a plate which is used as a pressing board to force the sand inside or compress it. This machine is mostly used for SHALLOW patterns.

Right option is (b) False

The explanation is: The transportation of the moulds should be controlled. A mould cannot be PLACED on a ROLLER CONVEYOR and allowed to roll until it is stopped by any obstruction. For transportation, moulds are either CONVEYED on trains or remained in permanent flasks or pushed mechanically along a roller conveyor.

Right OPTION is (B) False

To explain: It is very important for an organization to have the initial CAPITAL for implementing mechanization. But, even though a foundry through mechanization may produce a certain casting at a cheaper price and MUCH of the price of casting is in the form of transportation cost from foundry to the place of USE.

The correct option is (b) False

Best EXPLANATION: Mechanization is ACTUALLY based on the machinery and equipment that ensures high accuracy and speed of operation, and automation is the one which DEALS with computer technology and electronic data processing that replaces human LABOUR with high tech machines. In mechanization, the equipment is UTILIZED to boost the production of castings.

Right option is (a) True

To explain I would SAY: The core sand must be COLLAPSIBLE in nature, i.e. it should be disintegrate easily after the METAL solidifies in the mould cavity, this property can ease the cleaning of the castings. For a sufficient DEGREE of collapsibility, ADEQUATE core binders should be used in core making process which also increases strength of core.

The correct choice is (a) True

The explanation: Mechanization is only suitable for mass PRODUCTION because the initial COST, power USAGE, and maintenance costs INVOLVED are very higher than any other method. Small type production will not be profitable in a mechanized system. So, a large type of production should have mechanization for high productivity.

The correct option is (a) True

The explanation: Casting QUALITY is CONSIDERED as an important parameter, this basically satisfies the customer requirements. To achieve and maintain quality in production, it is very necessary to control the production process FIRSTLY. Manual control cannot FULFILL to attain the expected quality of castings. So, mechanization or MODERNIZATION is introduced to manage and control the process efficiently.

The correct choice is (b) False

The best I can explain: Vacuum moulding is very DIFFERENT from other TYPES of a moulding PROCESS. In this method, water is not used in mould mixture that reduces CHANCES of DEFECTS in the castings. But, the processes involved in vacuum moulding are very slow and this method cannot be adaptable to mechanization.

The CORRECT answer is (a) True

The best I can EXPLAIN: By mechanization and modernization in the PRODUCTION of castings, fatigue and strain on the workers considerably reduce during working, and WORK culture also improves itself tremendously. Efficient working in production can lead to a SENSE of participation, involvement, and creativity.

Correct choice is (b) False

The best I can explain: IMPLEMENTATION of mechanization in any foundry increases the production rate and also REDUCES the operating cost in LARGE volume production of castings. In mechanized foundry overall cost except for maintenance cost DECREASES and the process takes PLACE in less time too with high accuracy.

The correct CHOICE is (a) Increases

Explanation: 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.

The correct option is (a) True

Easiest explanation: In the mechanized foundry, USE of sand with more BOND strength can LESSEN the moisture content in the mould MIXTURE, or additional sand storage capacity can also enable the sand to cool that might eliminate the moisture PROBLEM in the mould. Moisture content should be kept balanced in mould making process.

Right option is (a) True

The EXPLANATION is: ZINC BASED foundry alloys with aluminium content have high strength and good tribiological properties, but due to their low structural stability over a long time that RESTRICTS their wider application in modern areas in the mechanization of foundry processes. This also reduces ductility due to the formation of dendritic STRUCTURE.

The CORRECT choice is (d) Thermo-setting resin

For explanation: Thermo-setting resin is very popular in core making because it imparts high strength, collapsibility to core sand and it ALSO emits a minimum amount of MOULD and core gases which can PRODUCE defects in the casting component. The most general BINDERS under this category are phenol formaldehyde and urea formaldehyde.

The correct answer is (B) False

Easy EXPLANATION: The methods and techniques involved in mechanized foundry for production of CASTINGS can change considerably, but the METAL casting is the oldest manufacturing PROCESS, so the fundamental principles or laws associated with the manufacturing remain almost the same in the process.

Correct option is (b) False

Easiest explanation: Preparation of uniform and homogenous MIXTURE of core sand cannot be POSSIBLE manually. So for better and uniform core sand properties using PROPER sand constituents and binders, the core sands are generally blended with the help of roller mills or core sand mixer which uses VERTICAL revolving arm type and horizontal paddle type mechanisms.

The correct CHOICE is (a) True

To elaborate: The method of SCRUBBING or cleaning is mainly USED for removing the gates from the casting; this process USES a scrubbing cylinder which cannot be used for excessively large castings because this process tends to crack the smaller parts of the casting. So, special techniques or more labours are employed for the process.

Correct option is (a) True

For explanation I would SAY: Difficulty arises by virtue of HIGH temperature of the MOLTEN METAL and its liquidity, spilling of the melt during pouring MAY freeze the roller conveyor. In the few instances when rubber conveyors have been tried, they were immediately discarded when a spillage of molten metal burnt the conveyors apart.

Correct choice is (b) False

Easy explanation: A mechanized foundry always produces CASTINGS of cheaper cost than any other foundry. But lacks of maintenance can results into low productivity because in the maintenance of expensive equipment requires SPECIALLY TRAINED maintenance men which basically results in HIGH cost of maintenance.

Right ANSWER is (b) False

The explanation is: The FIRST main consideration in mechanizing a foundry is the investment that MUST yield a profit. Not only the COST of castings should be reduced, but the additional return on the investment should be enough to fulfill all the demand of an organization. And properties of casting are considered as secondary in MECHANIZATION.

Correct option is (c) 6 kg(F)/cm^2

For explanation I would say: 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)/cm^2.

Correct choice is (b) Decreases

The explanation: 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.

Right option is (a) True

To explain I WOULD say: The basic PRINCIPLE of core blowing machine constitutes of filling the core sands into the core boxes by using compressed air. The velocity of the air is kept high to GET a high velocity of core sand PARTICLES that ensures their DEPOSIT in every corner of the core box. On entering of core sand with high velocity, the shaping and ramming of core are performed simultaneously in the core box.

The correct OPTION is (a) True

For EXPLANATION I would say: Hand molding operation need a lot of time for COMPLETION and LABOR effort, but, in case of molding machines, the equipment needed are costly, making the overall process an expensive one.

The CORRECT option is (d) Crane

Explanation: In foundry, the assembly of moulds and cores on a conveyor are carried to the casting station where the liquid metal is POURED by the ladle which is SUSPENDED by the application of crane, and then moulds filled with liquid metal are COOLED as they pass through the COOLING tunnel and at last arrive at the knockout station for extraction of castings.

Right answer is (b) False

The BEST explanation: In the mechanized system, tools help to simulate the casting solidification during processing. It enables the way to design the casting correctly and hence to avoid defects like hot spots and also to IDENTIFY and indicate the stress concentration zones. It PROVIDES temperature history of CASTINGS, detailed INFORMATION on the temperature contours inside the solidifying casting.

The correct option is (a) True

Explanation: By implementing mechanization in production, it can eliminate the application of moulding machines which reduces the amount of MAINTENANCE expense associated with the production of CASTINGS. This also terminates the use of other IDLE machines that RESULTS in optimization and saving of large CAPITAL.

Right option is (b) False

Explanation: In mechanized foundry, insertion of cores in MOULD is not EASY. Cores, which are an important PART of every mould, should still be inserted into the moulds MANUALLY. It is a very important drawback in mechanized foundry, the insertion of the cores remains as a STRENUOUS operation.

Right option is (a) True

Best explanation: In sand handling SYSTEM of mechanized foundry, the moulds are TAKEN out in a shaking MANNER that will allow the sand to be transported back to the CONDITIONING plant through the CONVEYOR belt. In this method, the process is easily accomplished without going into the various methods of sand handling.

The correct option is (b) False

Explanation: The cores are compact mass of core sand which is a SPECIAL kind of sand. And cores are always prepared SEPARATELY and then PLACED in mould CAVITY at a required location with proper alignment and accuracy. Core does not allow the liquid metal to OCCUPY space for solidification in that part and hence help to produce hollowness in the casting component.

Correct option is (a) True

Easiest EXPLANATION: In the core making process, the permeability of the core SAND should be SUFFICIENTLY high as compared to that of the moulding sand. So the core gases easily escape through the area of the core recesses which is generated by the core prints. And the core sand should also be of HIGHLY REFRACTORINESS in nature to sustain high temperature of molten metal.

Right CHOICE is (b) Quenching

For explanation I WOULD say: 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.

Correct answer is (b) False

Best explanation: In the core making process, core SAND is USED which is also known as oil sand. It is high rich silica sand that blends with oil binders such as core oil which is a combination of linseed oil, resin, mineral oil and other bind substances. Flours and water can also be used in making of large CORES which is a very economical WAY.

Right answer is (C) 15 cm

To elaborate: 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.

Right choice is (B) False

The explanation is: High bonding strength of sand in mould mixture and its thickness does not avoid the PROBLEM of sand inclusion in machine parts greatly, and even this reduces permeability of MOULDING mixture in a great amount which results into the FORMATION of castings with defects like blow holes.

Correct choice is (a) True

The best explanation: In the case of ROLLER mills, the rolling function of the mulling MACHINE along with the turning over movement caused by the ploughs gives a satisfactory and HOMOGENEOUS MIXING of core sand. Roller mills are only suitable for core SANDS that contain cereal binders, whereas the core sand mixer can be suitable for all types of core binders.

The CORRECT choice is (b) Decreases

The EXPLANATION is: 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.

Right answer is (b) 7 kg(F) /cm^2

The explanation: 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) /cm^2.

The correct choice is (b) False

Easy explanation: In the mechanized FOUNDRY, the gates are break off from the castings without any subsequent damage to the CASTING part itself. This is achieved by redesigning the gates practically from all of the PATTERNS so that the cross-section of the GATE reduces enough to enable it to break off at that point without damaging the casting.

Correct choice is (a) True

To elaborate: Even after having EXPENSIVE mechanization in foundry of castings, it has been studied in the all of its financial aspects that its economic success mainly DEPENDS to the existence of a great demand that is enough to JUSTIFY the increased output in the PRODUCTION of castings, which directly indicates HIGH productivity in an organization.