Category: Manufacturing Engineering Objective Questions

250+ TOP MCQs on Friction Welding and Answers

Manufacturing Processes Questions and Answers for Campus interviews on “Friction Welding”.

1. Friction welding process is restricted to_____
a) square bars
b) round bars
c) hexagonal bars
d) bars having diameters less than 20mm

Answer: b
Clarification: The process is restricted to joining round bars of same diameter (or bar tubes to flat surfaces), i.e., capable of being rotated about the axis. Furthermore, capital equipment and tooling costs are high and free-machining alloys are difficult to weld.

2. Which of the following materials cannot be welded by friction welding?
a) Aluminium
b) Copper
c) Stainless steel
d) Non-forgeable materials

Answer: d
Clarification: Dry bearing and non-forgeable materials cannot be welded by a friction welding process, i.e., one of the components must be ductile when hot, to permit deformations. Preparation and alignment of the workpieces of the workpieces may be critical for developing for developing uniform rubbing and heating, particularly for pieces having diameters larger than 50mm.

3. In which of the following areas, friction welded products are not used?
a) Aerospace
b) Automotive
c) Marine
d) Toy making

Answer: d
Clarification: Friction welded parts in production application span over wide products for aerospace, agriculture, automotive, defence, marine and oil industries. Right from tong holds to critical aircraft engine components are friction welded in production.

4. Which of the following automotive components are not friction-welded?
a) Gears
b) Engine valves
c) Strut rods
d) Rims

Answer: d
Clarification: Automotive parts that are friction welded include gears, engine valves, axel tubes, driveline components, strut rods and shock absorbers. Rims are generally welded by TIG or MIG welding.

5. Friction welding cannot be used for welding stainless steel to carbon steels.
a) True
b) False

Answer: b
Clarification: Stainless steels are friction welded to carbon steels in various sizes for uses in marine systems and water pumps for home and industrial use. Friction welded aluminium/copper joints are in wide usage in the electrical industry.

6. Friction welded components are cheaper than casted components.
a) True
b) False

Answer: b
Clarification: Friction welded components are comparatively cheaper than casted components. Friction welded assemblies are often used to replace expensive casted and forged components.

7. Which of the following components from agricultural equipment is not friction welded?
a) Track rollers
b) Axles
c) Bushings
d) Cultivator

Answer: d
Clarification: Following are the few components which are friction welded by manufacturers of agricultural equipment;
• Hydraulic piston rods
• Track rollers
• Gears
• Bushings
• Axles
Cultivators are heavy duty machines used for soil cultivation.

8. Aluminium is difficult to friction weld because of _____
a) ductility
b) softness
c) micro porosity
d) heat reflectivity

Answer: c
Clarification: The basic problems with friction welding of aluminium and its alloys are that they possess:
• Cast brittle dendritic structure
• Micro porosity
• Loss of strength in heat affected zone
• Solidification and liquation cracking
• Fatigue properties.

9. Which of the following processes can be used as alternative technique for joining aluminium and its alloys?
a) Tungsten inert-gas welding
b) Metal inert-gas welding
c) Friction stir welding
d) Oxy-Acetylene flame technique

Answer: c
Clarification: The following alternate techniques are being used for joining of aluminium and its alloys:
• Electron beam welding
• Laser beam welding
• Variable polarity plasma arc welding
• Friction stir welding.

10. Which of the following is not true about friction stir welding?
a) It is a solid state process
b) Fine grained structures can be obtained
c) It eliminates friction welding problems
d) It alters the chemical composition of the workpiece

Answer: d
Clarification: Following are the advantages of friction stir welding:
• It is a solid state process
• Fine grained, re-crystallized microstructures can be obtained
• It eliminates friction welding problems
• There is no significant alteration of chemical composition
• Routinely used to join difficult to friction weld alloys.

250+ TOP MCQs on Wire-cut EDM – 7 and Answers

Manufacturing Processes Multiple Choice Questions on “Wire-cut EDM – 7”.

1. In wire cut EDM machine, _______ axes are positioned away from the work area to avoid moisture and contamination.
a) X and Y
b) X and Z
c) U and V
d) Y and V
Answer: c
Clarification: The rigid U and V axis is positioned away from the work area to avoid moisture, contamination and deflection from the high pressure flush. Most Wire EDM’s are equipped with a programmable “Z” axis giving precise control of the upper guide assembly to ensure accurate tapers.

2. The U and V axes provide movement to the wire to produce taper angles upto _____ degrees.
a) 15
b) +/- 20
c) +/- 30
d) 45
Answer: c
Clarification: These axes provide movement to the top portion of the wire to produce taper angles of up to +/- 30 degrees. Both conical and oblique cylindrical radii can be programmed, and the size of the top and bottom radii of the part can also be programmed.

3. During the wire cut EDM process, the feature of adjustable tapering values is useful for _____
a) circular workpieces
b) mould applications
c) thick workpieces
d) forging dies
Answer: b
Clarification: Tapering values can be changed within the program. This is useful for mold applications or form tools that have different side and frontal taper relief angles. Die blocks are normally machined first with their taper relief, then straight cut for their die land.

4. The function of independent programming of the U & V axes in wire cut EDM machines is for _______
a) hexagonal workpieces
b) fullerene shaped workpieces
c) workpieces having a different shape on the top and bottom
d) workpieces having intricate shapes
Answer: c
Clarification: Wire cut EDM machines have U / V travels for providing the movement to cut tapers. Independent programming of the U & V axes is for workpieces that have a different shape on the top and bottom.

5. Which of the following is not machined by wire cut EDM?
a) airfoils
b) extrusion dies
c) square shaped objects
d) perforated sheets
Answer: d
Clarification: The independent, simultaneous movement of all four axes (X, Y, U, V) makes machining extrusion dies, airfoil shapes, and “squircles” (a square shape on the top, and a circle on the bottom of the workpiece) quite easy.

6. How many sections does the di-electric system includes?
a) 2
b) 3
c) 4
d) 5
Answer: c
Clarification: The dielectric system includes:
• the water reservoir
• filtration system
• de-ionization system
• water chiller unit.

7. While machining, the dirty water is filtered through a _____
a) paper filter
b) notch filters
c) comb filters
d) fir filters
Answer: a
Clarification: During cutting, the dirty water is drained into the unfiltered side of the dielectric reservoir where the water is then pumped and filtered through a paper filter, and returned to the clean side of the dielectric tank.

8. In a wire cut EDM machine, _____ is used to control the resistivity of the de-electric fluid (water).
a) resin beds
b) water reservoir
c) de-ionisation system
d) diamond guides
Answer: a
Clarification: Following filtration, the clean water is measured for conductivity, and if required passes through a vessel that contains a mixed bed of anion and cation beads. This mixed bed resin (the ion exchange unit) controls the resistivity of the water to set values automatically.

9. A water chiller is used to keep _____ thermally stable.
a) electrode wire
b) electrode coils
c) control arms
d) dielectric reservoir
Answer: c
Clarification: A water chiller is provided as standard equipment to keep following systems thermally stable:
• the dielectric
• workpiece
• worktable
• control arms
• fixtures.

10. During the cutting process water conductivity level changes due to eroded chips.
a) True
b) False
Answer: a
Clarification: During the cutting process the chips from the material that is being eroded, gradually changes the water conductivity level. Resistivity levels of the water are set according to the cutting requirements of the workpiece material being machined.

250+ TOP MCQs on Annealing – 8 and Answers

Manufacturing Processes Objective Questions & Answers on “Annealing – 8”.

1. The ratio of ______ is frequently used in the interpretation of recrystallization data.
a) yield strength of test specimen and standard specimen
b) temperature and time
c) rate of nucleation and rate of growth
d) rate of recrystallization and polygonization
Answer: c
Clarification: The ratio of the rate of nucleation to the rate of growth, N to G, is frequently used in the interpretation of recrystallization data. If it is assumed that both N and G are constant or are average values for an isothermal recrystallization process, then the recrystallized grain size can be deduced from this ratio.

2. Many nuclei will form before the recrystallization process is completed if the ratio of the rate of nucleation to the rate of growth is _____
a) high
b) low
c) equal to 1
d) higher than rate of grain growth
Answer: a
Clarification: If the ratio is high, many nuclei will form before the recrystallization process is completed, and a fine-grain size will result. On the other hand, a low ratio corresponds to a slow rate of nucleation relative to the rate of growth, and to a coarse crystal size in a recrystallized specimen.

3. The ratio N to G decreases in magnitude with decreasing _____
a) temperature
b) stress
c) strain
d) grain size
Answer: c
Clarification: As the deformation before annealing is reduced to smaller and smaller values, the rate of nucleation falls much faster than the rate of growth. As a consequence, the ratio N to G decreases in magnitude with decreasing strain and is effectively zero at several percent elongation.

4. The rate of recrystallization is dependent upon how many variables?
a) 2
b) 3
c) 4
d) It is an independent value
Answer: c
Clarification: The rate of recrystallization is dependent upon the following variables:
• temperature of annealing and
• amount of deformation
• purity of the metal
• initial grain size
The recrystallized grain size is independent of the annealing temperature but sensitive to the amount of strain.

5. Which of the following materials has rapid rates of recrystallization?
a) Pure metals
b) Alloys
c) Ductile metals
d) Coinage metal
Answer: a
Clarification: Extremely pure metals have very rapid rates of recrystallization. As little as 0.01% of a foreign atom in solid solution can raise the recrystallization temperature by several hundred degrees.

6. The increase in the recrystallization temperature caused due to foreign atoms depends on _____
a) nature of foreign atoms
b) temperature of foreign atoms
c) size of foreign atoms
d) electronegativity of foreign atoms
Answer: a
Clarification: The increase in the recrystallization temperature caused by the presence of foreign atoms depends markedly upon the nature of the solute atoms. The fact that very small numbers of solute atoms have such a pronounced effect on recrystallization rates is believed to indicate that the solute atoms interact with grain boundaries.

7. Decreasing the grain size increases the _____
a) recrystallization time
b) nucleation rate
c) grain boundary area
d) recrystallization temperature
Answer: c
Clarification: Decreasing the grain size increases the grain-boundary area and, as a consequence, the volume and uniformity of distorted metal (that adjacent to the boundaries). This effect increases the number of possible sites of nucleation and, therefore, the smaller the grains of the metal before cold work, the greater will be the rate of nucleation and the smaller the recrystallized grain size for a given degree of deformation.

8. _____ is the driving force for grain growth.
a) Strain
b) Surface energy
c) Recrystallization
d) Surface hardness
Answer: b
Clarification: The driving force for grain growth lies in the surface energy of the grain boundaries. As the grain grow in size and their numbers decrease, the grain boundary area diminishes and the total surface energy is lowered accordingly.

9. Annealing of a slightly deformed metal specimen can lead to a localized, very coarse-grain growth.
a) True
b) False
Answer: a
Clarification: If only a portion of a metallic object is deformed cold, a region containing a critical amount of cold work must exist between the worked and unworked areas. Annealing in this case can easily lead to a localized, very coarse-grain growth.

10. Foreign atoms lowers the recrystallization rates.
a) True
b) False
Answer: a
Clarification: When a foreign atom migrates to a grain boundary, both its elastic field, as well as that of the boundary, are lowered. In recrystallization, grain-boundary motion occurs as the nuclei form and grow. The presence of foreign atoms in atmospheres associated with these boundaries strongly retards their motion and therefore lowers the recrystallization rates.

To practice all objective questions on Manufacturing Processes,

250+ TOP MCQs on Non-Destructive Testing and Answers

Manufacturing Engineering Multiple Choice Questions on “Non-Destructive Testing”.

1. What is first step involved in the process of preparing test sample for microstructural examination?
a) Rough polishing
b) Fine grinding
c) Fine polishing
d) Etching
Answer: b
Clarification: Fine grinding involves the use of abrasive silicon carbide, to get a flat surface, that is nearly free of the disturbed or deformed scratches which were introduced in the previous sample preparation step. For reference, the sample preparation steps are depicted in the below schematic:

2. Which of the following compound is used for fine polishing?
a) Aluminum oxide
b) Nitric oxide
c) Silicon carbide
d) Iron oxide
Answer: a
Clarification: Powder form of aluminum oxide is used for fine polishing process. It is surface treatment process.

3. Etching of specimen is done to achieve ___________
a) Visible grain boundary
b) Invisible grain boundary
c) Toughness
d) Hardness
Answer: a
Clarification: Etching is done to obtain visible grain boundary. It is a surface treatment process.

4. What is the average grain diameter (in mm) for the grain size ASTM grain size 12?
a) .0066
b) .0078
c) .0021
d) .0056
Answer: d
Clarification: According to ASTM standard E1112, ”standard test methods for determining average grain size”:
n = 2G-1, where ‘G’ is the grain size number and ‘n’ represents the average number of grains per square inch at a magnification of 100X. Upon calculations one can deduce that:
Average Grain diameter (d, in mm) = (frac{1}{sqrt{frac{n×10^4}{645}}})
Given ASTM grain size 12, thus, n = 212-1 = 211 = 2048
Therefore, average grain diameter = (frac{1}{sqrt{frac{2048×10^4}{645}}}) = 0.0056 mm.

5. Equipment used for inspection of inside portion of hollow chamber or narrow tube is known as ___________
a) Endoscope
b) Telescope
c) Borescope
d) Flexiscope
Answer: c
Clarification: Borescope is used for visual of inside portion of the hollow chamber.

6. What is the value of average number of grains in per square inch for ASTM 11?
a) 2048
b) 1024
c) 6
d) 5
Answer: b
Clarification: According to ASTM standard E1112, ”standard test methods for determining average grain size”:
n = 2G-1, where ‘G’ is the grain size number and ‘n’ represents the average number of grains per square inch at a magnification of 100X.
Given ASTM grain size 12, thus, n = 211-1 = 210 = 1024.

7. Which of the following property will be more in fine grained structure?
a) Ductility
b) Corrosion resistance
c) Creep resistance
d) Hardness
Answer: a
Clarification: Finer the grain size (lower the grain size), more is the number of grain boundaries, thus more is the yield strength, thus more is the ductility. This is the reason why we can easily draw a fine-grained structure into wires.

8. Which of the following property will be more in coarse grain structure?
a) Ductility
b) Corrosion resistance
c) Hardness
d) Toughness
Answer: a
Clarification: Grain boundaries are susceptible to corrosion. Coarse grain structure has less grain boundaries, thus has greater corrosion resistance.

9. Which of the following penetrating liquid is used in a liquid penetration test?
a) Water
b) Chlorine based solvent
c) Petroleum based carrier fluid
d) Fluorine based solvent
Answer: c
Clarification: In liquid penetration test, either petroleum-or-water based carrier fluids are used as solvents or cleaners according to the type of penetrant used. Petroleum based carrier fluid is used as penetrating liquid in liquid penetration test along with fluorescent red colour dye for visible light.

10. Which of the following non destructive testing is used to detect change in composition of any material?
a) Liquid penetration test
b) Ultrasonic test
c) Eddy current test
d) Radiography
Answer: d
Clarification: Radiography enables us to detect the change in composition. X-rays or γ-rays are used in radiography technique.

250+ TOP MCQs on Cutting Tool Material-2 and Answers

Manufacturing Engineering Multiple Choice Questions on “Cutting Tool Material-2”.

1. What is the percentage of carbon tungsten in T-series of high speed steel?
a) 20
b) 18
c) 16
d) 14
Answer: b
Clarification: 18% of tungsten is present in T-series of high speed steel. It is used for cutting at low speeds rather than at high speed as its name implies but it cuts faster.

2. What is the percentage of carbon chromium in T-series of high speed steel?
a) 0
b) 8
c) 6
d) 4
Answer: d
Clarification: 4% of chromium is present in T-series of high speed steel. It is used for cutting at low speeds rather than at high speed as its name implies but it cuts faster.

3. What is the percentage of vanadium in T-series of high speed steel?
a) 2
b) 1
c) 6
d) 4
Answer: b
Clarification: 1% of vanadium is present in T-series of high speed steel. It is used for cutting at low speeds rather than at high speed as its name implies but it cuts faster.

4. What is the percentage of Molybdenum in M-series of high speed steel?
a) 12
b) 21
c) 16
d) 24
Answer: b
Clarification: 21% of molybdenum is present in M-series of high speed steel. It is used for cutting at low speeds rather than at high speed as its name implies but it cuts faster.

5. M-series high speed steel has more efficiency than T-series high speed steel.
a) True
b) False
Answer: a
Clarification: M series have more cutting efficiency than T series high speed steel. It is used for cutting at low speeds rather than at high speed as its name implies but it cuts faster.

6. Presence of Chromium in T-series steel imparts
a) Hardness
b) Corrosion resistance
c) Abrasion resistance
d) Toughness
Answer: b
Clarification: Chromium imparts corrosion and oxidation resistance to a material. It is used for cutting at low speeds rather than at high speed as its name implies but it cuts faster.

7. Which of the following element is responsible for providing red hot hardness property to T-series high speed steel?
a) W
b) Cr
c) V
d) Mo
Answer: a
Clarification: Tungsten imparts red hot hardness i.e. property to impart hardness at high temperature. HSS is used for cutting at low speeds rather than at high speed as its name implies but it cuts faster.

8. If percentage of cobalt in Tungsten carbide tool increases, then the strength of the tool will
a) Increase
b) Decrease
c) Remains Constant
d) First increase then decrease
Answer: b
Clarification: With an increase in the percentage of cobalt hardness decreases. HSS is used for cutting at low speeds rather than at high speed as its name implies but it cuts faster.

9. If percentage of cobalt in Tungsten carbide tool increases, then hardness of tool will
a) Increase
b) Decrease
c) Remains Constant
d) First increase then decrease
Answer: b
Clarification: With an increase in the percentage of cobalt, hardness and strength decreases.

10. If percentages of cobalt in Tungsten carbide tool increases, then wear resistance of tool will
a) Increase
b) Decrease
c) Remains Constant
d) First increase then decrease
Answer: b
Clarification: With increase in the percentage of cobalt hardness, strength and wear resistance decreases.

250+ TOP MCQs on Shaper Parts and Answers

Manufacturing Engineering Multiple Choice Questions on “Shaper Parts”.

1. Cutting of material during shaping operation takes place in
a) Forward stroke
b) Backward stroke
c) Both forward and backward stroke
d) None of the mentioned
Answer: a
Clarification: Cutting always takes place in forward stroke. Backward stroke is ideal stroke.

2. Which of the following part of shaper supports all of the other parts of machines?
a) Base
b) Column
c) Cross rail
d) Table
Answer: a
Clarification: Base act as support for all other parts. It is made of stronger material.

3. Cutting of material during slotting operation takes place in
a) Forward stroke
b) Backward stroke
c) Both forward and backward stroke
d) None of the mentioned
Answer: a
Clarification: Cutting always takes place in forward stroke. Backward stroke is ideal stroke.

4. Which of the following act as housing for an operating mechanism in shaper?
a) Base
b) Column
c) Cross rail
d) Table
Answer: b
Clarification: Column acts as housing for operating mechanism in shaper. It is made of stronger material.

5. Which of the following part of shaper machine carries table elevating mechanism?
a) Base
b) Column
c) Cross rail
d) Table
Answer: c
Clarification: Cross rail carries table elevating mechanism. It is used to raise the of the table.

6. Which of the following part of shaper machine carries vertical guide ways mechanism?
a) Base
b) Column
c) Cross rail
d) Table
Answer: c
Clarification: Cross rail carries vertical guide ways mechanism. Cross rail carries table elevating mechanism. It is used to raise the of table.

7. Which of the following part of shaper machine hold and supports the work piece?
a) Base
b) Column
c) Cross rail
d) Table
Answer: d
Clarification: Table supports work piece. It is made of harder material.

8. Which of the following part of shaper machine carries tool head?
a) Cross rail
b) Column
c) Ram
d) Table
Answer: c
Clarification: Ram carries tool head. It also carries mechanism for tool head movement.

9. Which of the following part of shaper provides straight line motion of tool?
a) Cross rail
b) Column
c) Ram
d) Table
Answer: c
Clarification: Ram carries tool head and provides straight line motion to a tool.

10. Which of the following part of shape is used to hold the tool?
a) Cross rail
b) Tool head
c) Ram
d) Vice
Answer: b
Clarification: Tool head is used for tool holding purpose. It is attached to ram.

11. Which of the following can be used as job holding device in shaping machine?
a) Cross rail
b) Column
c) Ram
d) Vice
Answer: d
Clarification: Vice is a job holding device. It have good efficiency as holding device.