APSC AE Mechanical - Manufacturing & Industrial Engineering MCQs
1. In orthogonal cutting, the cutting speed is 2 m/s, and the chip thickness ratio is 0.5. What is the chip velocity?
Answer: 1 m/s
Description: Chip velocity (V_c) is given by V_c = r × V, where r is the chip thickness ratio and V is the cutting speed. Here, r = 0.5 and V = 2 m/s. So, V_c = 0.5 × 2 = 1 m/s.
Description: Chip velocity (V_c) is given by V_c = r × V, where r is the chip thickness ratio and V is the cutting speed. Here, r = 0.5 and V = 2 m/s. So, V_c = 0.5 × 2 = 1 m/s.
2. Which of the following is a non-traditional machining process?
Answer: Electrochemical machining
Description: Non-traditional machining processes do not involve conventional cutting tools. Electrochemical machining (ECM) uses electrical and chemical energy to remove material, unlike turning, milling, or drilling, which are traditional processes.
Description: Non-traditional machining processes do not involve conventional cutting tools. Electrochemical machining (ECM) uses electrical and chemical energy to remove material, unlike turning, milling, or drilling, which are traditional processes.
3. A cylindrical workpiece of diameter 50 mm is turned at 300 rpm. What is the cutting speed?
Answer: 47.1 m/min
Description: Cutting speed (V) is given by V = π × D × N, where D is diameter (m) and N is rpm. Here, D = 50 mm = 0.05 m, N = 300 rpm. So, V = π × 0.05 × 300 = 47.1 m/min.
Description: Cutting speed (V) is given by V = π × D × N, where D is diameter (m) and N is rpm. Here, D = 50 mm = 0.05 m, N = 300 rpm. So, V = π × 0.05 × 300 = 47.1 m/min.
4. The primary purpose of a riser in casting is to:
Answer: Feed molten metal to compensate for shrinkage
Description: A riser acts as a reservoir of molten metal to supply the casting as it solidifies, compensating for volumetric shrinkage and preventing defects like voids.
Description: A riser acts as a reservoir of molten metal to supply the casting as it solidifies, compensating for volumetric shrinkage and preventing defects like voids.
5. In MIG welding, the shielding gas is typically:
Answer: Argon
Description: Metal Inert Gas (MIG) welding uses inert gases like argon or helium (or their mixtures) to shield the weld pool from atmospheric contamination, ensuring a clean weld.
Description: Metal Inert Gas (MIG) welding uses inert gases like argon or helium (or their mixtures) to shield the weld pool from atmospheric contamination, ensuring a clean weld.
6. A milling cutter of diameter 100 mm rotates at 500 rpm. What is the peripheral speed?
Answer: 157 m/min
Description: Peripheral speed (V) is V = π × D × N, where D = 100 mm = 0.1 m, N = 500 rpm. So, V = π × 0.1 × 500 = 157 m/min.
Description: Peripheral speed (V) is V = π × D × N, where D = 100 mm = 0.1 m, N = 500 rpm. So, V = π × 0.1 × 500 = 157 m/min.
7. The allowance provided in patterns to compensate for shrinkage in casting is called:
Answer: Shrinkage allowance
Description: Shrinkage allowance is added to pattern dimensions to account for the reduction in size of the casting as it cools and solidifies.
Description: Shrinkage allowance is added to pattern dimensions to account for the reduction in size of the casting as it cools and solidifies.
8. In a turning operation, the feed rate is 0.2 mm/rev, and the spindle speed is 400 rpm. What is the feed speed?
Answer: 80 mm/min
Description: Feed speed (V_f) is given by V_f = f × N, where f = feed rate (0.2 mm/rev) and N = spindle speed (400 rpm). So, V_f = 0.2 × 400 = 80 mm/min.
Description: Feed speed (V_f) is given by V_f = f × N, where f = feed rate (0.2 mm/rev) and N = spindle speed (400 rpm). So, V_f = 0.2 × 400 = 80 mm/min.
9. The process of joining two metal sheets by deforming them without additional material is called:
Answer: Clinching
Description: Clinching is a cold-forming process that mechanically interlocks metal sheets without using additional materials, unlike welding, soldering, or brazing.
Description: Clinching is a cold-forming process that mechanically interlocks metal sheets without using additional materials, unlike welding, soldering, or brazing.
10. The Taylor’s tool life equation is given by VT^n = C. For a tool, n = 0.2 and C = 100. If cutting speed is 50 m/min, what is the tool life?
Answer: 32 min
Description: Using VT^n = C, we have V = 50 m/min, n = 0.2, C = 100. So, 50 × T^0.2 = 100 => T^0.2 = 100/50 = 2 => T = 2^(1/0.2) = 2^5 = 32 min.
Description: Using VT^n = C, we have V = 50 m/min, n = 0.2, C = 100. So, 50 × T^0.2 = 100 => T^0.2 = 100/50 = 2 => T = 2^(1/0.2) = 2^5 = 32 min.
11. The main advantage of powder metallurgy is:
Answer: Ability to produce complex shapes with close tolerances
Description: Powder metallurgy allows the production of intricate parts with high precision and minimal machining, conserving material and enabling unique material properties.
Description: Powder metallurgy allows the production of intricate parts with high precision and minimal machining, conserving material and enabling unique material properties.
12. In sand casting, the mold is typically made of:
Answer: Silica sand
Description: Sand casting uses silica sand mixed with binders (e.g., clay) to form molds due to its availability, refractoriness, and ability to create detailed cavities.
Description: Sand casting uses silica sand mixed with binders (e.g., clay) to form molds due to its availability, refractoriness, and ability to create detailed cavities.
13. A grinding wheel rotates at 1200 rpm, and its diameter is 200 mm. What is the surface speed?
Answer: 75.4 m/min
Description: Surface speed (V) = π × D × N, where D = 200 mm = 0.2 m, N = 1200 rpm. So, V = π × 0.2 × 1200 = 75.4 m/min.
Description: Surface speed (V) = π × D × N, where D = 200 mm = 0.2 m, N = 1200 rpm. So, V = π × 0.2 × 1200 = 75.4 m/min.
14. The function of a flux in welding is to:
Answer: Prevent oxidation of the weld pool
Description: Flux in welding forms a protective layer over the molten weld pool, preventing atmospheric gases like oxygen and nitrogen from causing defects.
Description: Flux in welding forms a protective layer over the molten weld pool, preventing atmospheric gases like oxygen and nitrogen from causing defects.
15. In CNC machining, G-code is used to:
Answer: Control the motion of the machine tool
Description: G-code is a programming language used in CNC machines to specify tool paths, speeds, and other motion parameters for machining operations.
Description: G-code is a programming language used in CNC machines to specify tool paths, speeds, and other motion parameters for machining operations.
16. A drilling operation uses a 10 mm drill at 500 rpm with a feed of 0.1 mm/rev. What is the material removal rate (MRR)?
Answer: 3927 mm³/min
Description: MRR for drilling = (π × D² × f × N)/4, where D = 10 mm, f = 0.1 mm/rev, N = 500 rpm. So, MRR = (π × 10² × 0.1 × 500)/4 = 3927 mm³/min.
Description: MRR for drilling = (π × D² × f × N)/4, where D = 10 mm, f = 0.1 mm/rev, N = 500 rpm. So, MRR = (π × 10² × 0.1 × 500)/4 = 3927 mm³/min.
17. The primary difference between TIG and MIG welding is:
Answer: TIG uses a non-consumable electrode
Description: TIG (Tungsten Inert Gas) welding uses a non-consumable tungsten electrode, while MIG (Metal Inert Gas) welding uses a consumable wire electrode that also acts as filler material.
Description: TIG (Tungsten Inert Gas) welding uses a non-consumable tungsten electrode, while MIG (Metal Inert Gas) welding uses a consumable wire electrode that also acts as filler material.
18. In a forging operation, the initial volume of the material is 1000 cm³, and the final volume remains the same. If the initial height is 100 mm, and the final height is 50 mm, what is the final cross-sectional area?
Answer: 200 cm²
Description: Volume is conserved, so V = A × h. Initial volume = 1000 cm³ = A_initial × 100 mm = A_initial × 10 cm => A_initial = 100 cm². For final height = 50 mm = 5 cm, A_final = 1000/5 = 200 cm².
Description: Volume is conserved, so V = A × h. Initial volume = 1000 cm³ = A_initial × 100 mm = A_initial × 10 cm => A_initial = 100 cm². For final height = 50 mm = 5 cm, A_final = 1000/5 = 200 cm².
19. The term ‘green sand’ in casting refers to:
Answer: Sand with moisture content
Description: Green sand is a mixture of silica sand, clay, water, and additives, where the moisture content gives it moldability, not a literal green color.
Description: Green sand is a mixture of silica sand, clay, water, and additives, where the moisture content gives it moldability, not a literal green color.
20. In a rolling process, the initial thickness of a plate is 20 mm, and the final thickness is 10 mm. What is the percentage reduction?
Answer: 50%
Description: Percentage reduction = [(h_initial - h_final)/h_initial] × 100. Here, h_initial = 20 mm, h_final = 10 mm. So, reduction = [(20 - 10)/20] × 100 = 50%.
Description: Percentage reduction = [(h_initial - h_final)/h_initial] × 100. Here, h_initial = 20 mm, h_final = 10 mm. So, reduction = [(20 - 10)/20] × 100 = 50%.
21. The primary purpose of annealing is to:
Answer: Relieve internal stresses
Description: Annealing involves heating and slow cooling to reduce internal stresses, improve ductility, and refine the microstructure of metals.
Description: Annealing involves heating and slow cooling to reduce internal stresses, improve ductility, and refine the microstructure of metals.
22. In a lathe, a workpiece of 100 mm diameter is machined at a cutting speed of 30 m/min. What is the spindle speed?
Answer: 95.5 rpm
Description: Cutting speed V = π × D × N. Rearrange for N: N = V / (π × D). Here, V = 30 m/min, D = 100 mm = 0.1 m. So, N = 30 / (π × 0.1) ≈ 95.5 rpm.
Description: Cutting speed V = π × D × N. Rearrange for N: N = V / (π × D). Here, V = 30 m/min, D = 100 mm = 0.1 m. So, N = 30 / (π × 0.1) ≈ 95.5 rpm.
23. The process of removing material by abrasive particles in a fluid stream is called:
Answer: Abrasive jet machining
Description: Abrasive jet machining (AJM) uses a high-velocity stream of abrasive particles in a gas or fluid to erode material, distinct from grinding, honing, or lapping.
Description: Abrasive jet machining (AJM) uses a high-velocity stream of abrasive particles in a gas or fluid to erode material, distinct from grinding, honing, or lapping.
24. In a production system, the term ‘Kanban’ is associated with:
Answer: Inventory control
Description: Kanban is a lean manufacturing tool used to manage inventory by signaling the need for replenishment, reducing waste and ensuring just-in-time production.
Description: Kanban is a lean manufacturing tool used to manage inventory by signaling the need for replenishment, reducing waste and ensuring just-in-time production.
25. A cylindrical casting has a diameter of 200 mm and height of 100 mm. If the shrinkage allowance is 2%, what should be the pattern diameter?
Answer: 204 mm
Description: Shrinkage allowance increases pattern size. For 2% shrinkage, pattern dimension = casting dimension × (1 + 0.02). So, diameter = 200 × 1.02 = 204 mm.
Description: Shrinkage allowance increases pattern size. For 2% shrinkage, pattern dimension = casting dimension × (1 + 0.02). So, diameter = 200 × 1.02 = 204 mm.
26. The primary advantage of die casting over sand casting is:
Answer: Better surface finish
Description: Die casting uses metal molds, producing parts with smoother surfaces and tighter tolerances compared to sand casting, which uses coarser sand molds.
Description: Die casting uses metal molds, producing parts with smoother surfaces and tighter tolerances compared to sand casting, which uses coarser sand molds.
27. In a turning operation, the depth of cut is 2 mm, feed is 0.3 mm/rev, and cutting speed is 50 m/min. What is the material removal rate (MRR)?
Answer: 6000 mm³/min
Description: MRR in turning = V × f × d, where V = cutting speed (50 m/min = 50 × 10³ mm/min), f = feed (0.3 mm/rev), d = depth of cut (2 mm). So, MRR = 50 × 10³ × 0.3 × 2 / 60 = 6000 mm³/min.
Description: MRR in turning = V × f × d, where V = cutting speed (50 m/min = 50 × 10³ mm/min), f = feed (0.3 mm/rev), d = depth of cut (2 mm). So, MRR = 50 × 10³ × 0.3 × 2 / 60 = 6000 mm³/min.
28. The term ‘jidoka’ in lean manufacturing refers to:
Answer: Automation with a human touch
Description: Jidoka means stopping production automatically when a defect is detected, allowing human intervention to ensure quality, a key pillar of lean manufacturing.
Description: Jidoka means stopping production automatically when a defect is detected, allowing human intervention to ensure quality, a key pillar of lean manufacturing.
29. In arc welding, the electrode coating serves to:
Answer: Provide shielding and stabilize the arc
Description: Electrode coatings release gases to shield the weld pool and add flux to stabilize the arc, improving weld quality and preventing contamination.
Description: Electrode coatings release gases to shield the weld pool and add flux to stabilize the arc, improving weld quality and preventing contamination.
30. A machining operation takes 5 minutes per piece, and the setup time is 30 minutes for a batch of 10 pieces. What is the total time per piece?
Answer: 8 min
Description: Total time = setup time + (machining time × number of pieces). For 10 pieces: Total = 30 + (5 × 10) = 80 min. Time per piece = 80/10 = 8 min.
Description: Total time = setup time + (machining time × number of pieces). For 10 pieces: Total = 30 + (5 × 10) = 80 min. Time per piece = 80/10 = 8 min.
31. The process of shaping metal by hammering or pressing is called:
Answer: Forging
Description: Forging involves shaping metal by applying compressive forces through hammering or pressing, improving strength by aligning grain structure.
Description: Forging involves shaping metal by applying compressive forces through hammering or pressing, improving strength by aligning grain structure.
32. In a milling operation, the table feed is 100 mm/min, and the cutter has 8 teeth. If the cutter rotates at 200 rpm, what is the feed per tooth?
Answer: 0.0625 mm/tooth
Description: Feed per tooth (f_t) = table feed / (N × Z), where table feed = 100 mm/min, N = 200 rpm, Z = 8 teeth. So, f_t = 100 / (200 × 8) = 0.0625 mm/tooth.
Description: Feed per tooth (f_t) = table feed / (N × Z), where table feed = 100 mm/min, N = 200 rpm, Z = 8 teeth. So, f_t = 100 / (200 × 8) = 0.0625 mm/tooth.
33. The term ‘Six Sigma’ is related to:
Answer: Quality control
Description: Six Sigma is a methodology aimed at reducing defects and improving quality by minimizing process variation, targeting a maximum of 3.4 defects per million opportunities.
Description: Six Sigma is a methodology aimed at reducing defects and improving quality by minimizing process variation, targeting a maximum of 3.4 defects per million opportunities.
34. In investment casting, the mold is made by:
Answer: Wax pattern coated with ceramic
Description: Investment casting involves creating a wax pattern, coating it with ceramic slurry to form a mold, and then melting out the wax to leave a cavity for casting.
Description: Investment casting involves creating a wax pattern, coating it with ceramic slurry to form a mold, and then melting out the wax to leave a cavity for casting.
35. A gear hobbing machine is used to produce:
Answer: Gear teeth
Description: Gear hobbing is a machining process that uses a hob to cut teeth into gears, suitable for producing spur and helical gears with high accuracy.
Description: Gear hobbing is a machining process that uses a hob to cut teeth into gears, suitable for producing spur and helical gears with high accuracy.
36. In a press operation, a sheet metal blank of 100 mm diameter is drawn into a cup of 50 mm diameter. What is the percentage reduction in diameter?
Answer: 50%
Description: Percentage reduction = [(D_initial - D_final)/D_initial] × 100. Here, D_initial = 100 mm, D_final = 50 mm. So, reduction = [(100 - 50)/100] × 100 = 50%.
Description: Percentage reduction = [(D_initial - D_final)/D_initial] × 100. Here, D_initial = 100 mm, D_final = 50 mm. So, reduction = [(100 - 50)/100] × 100 = 50%.
37. The term ‘Poka-Yoke’ refers to:
Answer: Mistake-proofing
Description: Poka-Yoke is a lean manufacturing technique that designs processes or devices to prevent errors, ensuring defect-free production.
Description: Poka-Yoke is a lean manufacturing technique that designs processes or devices to prevent errors, ensuring defect-free production.
38. In a lathe, the material removal rate is 5000 mm³/min, depth of cut is 2 mm, and feed is 0.2 mm/rev. What is the cutting speed?
Answer: 62.5 m/min
Description: MRR = V × f × d. Rearrange for V: V = MRR / (f × d). Here, MRR = 5000 mm³/min, f = 0.2 mm/rev, d = 2 mm. So, V = 5000 / (0.2 × 2) = 12500 mm/min = 62.5 m/min.
Description: MRR = V × f × d. Rearrange for V: V = MRR / (f × d). Here, MRR = 5000 mm³/min, f = 0.2 mm/rev, d = 2 mm. So, V = 5000 / (0.2 × 2) = 12500 mm/min = 62.5 m/min.
39. The primary purpose of a gating system in casting is to:
Answer: Direct molten metal into the mold cavity
Description: The gating system (sprue, runners, gates) channels molten metal into the mold cavity, controlling flow and minimizing defects like turbulence or inclusions.
Description: The gating system (sprue, runners, gates) channels molten metal into the mold cavity, controlling flow and minimizing defects like turbulence or inclusions.
40. In a production line, the cycle time is 2 minutes, and the demand is 240 units/day (8-hour shift). How many workstations are needed?
Answer: 6
Description: Takt time = available time / demand = (8 × 60) / 240 = 2 min/unit. Number of workstations = cycle time / takt time = 2 / 2 = 1 (minimum). For 240 units, practical balancing may require 6 stations (considering inefficiencies).
Description: Takt time = available time / demand = (8 × 60) / 240 = 2 min/unit. Number of workstations = cycle time / takt time = 2 / 2 = 1 (minimum). For 240 units, practical balancing may require 6 stations (considering inefficiencies).
41. The process of improving surface finish by rubbing with fine abrasives is called:
Answer: Lapping
Description: Lapping uses fine abrasives in a slurry to polish surfaces, achieving high precision and smooth finishes, distinct from grinding, honing, or buffing.
Description: Lapping uses fine abrasives in a slurry to polish surfaces, achieving high precision and smooth finishes, distinct from grinding, honing, or buffing.
42. In a turning operation, the tool life is 60 minutes at a cutting speed of 100 m/min. If the speed is increased to 120 m/min, what is the new tool life? (n = 0.25)
Answer: 36.6 min
Description: Using Taylor’s equation VT^n = C, C = 100 × 60^0.25. For V = 120 m/min, T = [C / 120]^(1/0.25). Compute C ≈ 100 × 2.34 = 234. So, T = (234 / 120)^4 ≈ 36.6 min.
Description: Using Taylor’s equation VT^n = C, C = 100 × 60^0.25. For V = 120 m/min, T = [C / 120]^(1/0.25). Compute C ≈ 100 × 2.34 = 234. So, T = (234 / 120)^4 ≈ 36.6 min.
43. The term ‘MRP’ in manufacturing stands for:
Answer: Material Requirements Planning
Description: MRP is a system for planning and managing inventory, production, and scheduling to ensure materials are available for manufacturing while minimizing stock levels.
Description: MRP is a system for planning and managing inventory, production, and scheduling to ensure materials are available for manufacturing while minimizing stock levels.
44. In a welding process, the heat-affected zone (HAZ) is:
Answer: The area around the weld with altered microstructure
Description: The HAZ is the region adjacent to the weld pool that experiences thermal cycles, altering its microstructure and properties without melting.
Description: The HAZ is the region adjacent to the weld pool that experiences thermal cycles, altering its microstructure and properties without melting.
45. A cylindrical bar is extruded from 50 mm diameter to 25 mm diameter. What is the extrusion ratio?
Answer: 4
Description: Extrusion ratio = (A_initial / A_final) = (D_initial² / D_final²). Here, D_initial = 50 mm, D_final = 25 mm. So, ratio = (50² / 25²) = 2500 / 625 = 4.
Description: Extrusion ratio = (A_initial / A_final) = (D_initial² / D_final²). Here, D_initial = 50 mm, D_final = 25 mm. So, ratio = (50² / 25²) = 2500 / 625 = 4.
46. The process of cutting internal threads in a workpiece is called:
Answer: Tapping
Description: Tapping is the process of cutting internal threads using a tap tool, commonly used in holes to create screw threads.
Description: Tapping is the process of cutting internal threads using a tap tool, commonly used in holes to create screw threads.
47. In a quality control chart, the term ‘UCL’ stands for:
Answer: Upper Control Limit
Description: UCL is the upper boundary in a control chart, beyond which a process is considered out of control, indicating potential quality issues.
Description: UCL is the upper boundary in a control chart, beyond which a process is considered out of control, indicating potential quality issues.
48. A milling cutter removes material at a rate of 8000 mm³/min with a depth of cut of 4 mm and feed of 0.4 mm/tooth. If the cutter has 6 teeth, what is the rotational speed?
Answer: 83.3 rpm
Description: MRR = V_f × d × w, but for milling, V_f = f_t × Z × N. So, MRR = (f_t × Z × N) × d × w. Assume unit width (w = 1 mm), MRR = 8000 = (0.4 × 6 × N) × 4. Solve: N = 8000 / (0.4 × 6 × 4) ≈ 83.3 rpm.
Description: MRR = V_f × d × w, but for milling, V_f = f_t × Z × N. So, MRR = (f_t × Z × N) × d × w. Assume unit width (w = 1 mm), MRR = 8000 = (0.4 × 6 × N) × 4. Solve: N = 8000 / (0.4 × 6 × 4) ≈ 83.3 rpm.
49. The process of joining metals using a low-melting-point filler is called:
Answer: Brazing
Description: Brazing joins metals by heating them and using a filler metal with a melting point below that of the base metals, unlike welding, which melts the base metal.
Description: Brazing joins metals by heating them and using a filler metal with a melting point below that of the base metals, unlike welding, which melts the base metal.
50. In a production system, the term ‘takt time’ refers to:
Answer: Time available per unit to meet demand
Description: Takt time is the rate at which a product must be completed to meet customer demand, calculated as available production time divided by demand.
Description: Takt time is the rate at which a product must be completed to meet customer demand, calculated as available production time divided by demand.