Multiple choice question for engineering
Set 1
1. Extrusion process is not suitable for which of the following?
a) Steel alloys
b) Non-ferrous alloys
c) Stainless steel
d) Iron
Answer
Answer: d [Reason:] Extrusion process is not suitable for any of the iron alloys, neither is it suitable for iron metal. For extruding stainless steel or other non-ferrous alloys or steel alloys, extrusion process can be used.
2. Which of the following is not made using extrusion?
a) Window frames
b) Doors
c) Helmets
d) Rods
Answer
Answer: c [Reason:] Among the following, helmets are not manufactured using extrusion, whereas all other products can be manufactured using extrusion.
3. What is the shape of the billet used in extrusion process?
a) Cubical
b) Spherical
c) Cylindrical
d) Pyramidal
Answer
Answer: c [Reason:] The shape of the billet in an extrusion process is designed to be cylindrical only. A cubical or spherical or a pyramidal billet cannot be designed for a good output.
4. Which of the following is also called as forward hot extrusion?
a) Direct extrusion
b) Indirect extrusion
c) Impact extrusion
d) Hydrostatic extrusion
Answer
Answer: a [Reason:] Direct extrusion is also called as forward hot extrusion. This method is most widely used and maximum production is done by this method in extrusion.
5. Backward extrusion is another name for which of the following?
a) Direct extrusion
b) Indirect extrusion
c) Impact extrusion
d) Hydrostatic extrusion
Answer
Answer: b [Reason:] Direct extrusion is also called as backward extrusion. In this method, the metal is extruded back into the plunger.
6. In which of the following operations is a dummy block used?
a) Indirect extrusion
b) Direct extrusion
c) Impact extrusion
d) Hydrostatic extrusion
Answer
Answer: b [Reason:] In direct extrusion or forward extrusion, a dummy block is used during the functioning of the extrusion process.
7. Indirect extrusion needs a large amount of force for functioning.
a) True
b) False
Answer
Answer: b [Reason:] Indirect extrusion or backward extrusion does not require large amount of force for operation, as the billet is stationery.
8. Up to what size can wires can be drawn by wire drawing process?
a) 0.01mm
b) 0.02mm
c) 0.03mm
d) 0.04mm
Answer
Answer: c [Reason:] It may be counted among one of the limitation of drawing process, that very thin wires can only be drawn from it. In wire drawing process, wires can be drawn up to the size of 0.03mm.
9. Which of the following metal is used in wire drawing process in die making?
a) Copper
b) Iron
c) Tungsten
d) Magnesium
Answer
Answer: c [Reason:] For making dies in wire extrusion process, copper or iron or magnesium cannot be used, but the compound tungsten carbide is used.
10. A solid ram is used in direct extrusion.
a) True
b) False
Answer
Answer: a [Reason:] A solid ram is used in direct extrusion or forward extrusion, whereas a hollow ram is used in indirect extrusion.
Set 2
1. Low carbon steels can be started to forge at what temperature?
a) 1140°C
b) 1270°C
c) 1350°C
d) 1420°C
Answer
Answer: b [Reason:] Low carbon soft steels are generally used for making seamless and welded steel pipes, which can be used at very low temperatures. They can be forged at a temperature range of 1250°C to 1300°C.
2. Low carbon steels get forged at what temperature?
a) 670°C
b) 730°C
c) 820°C
d) 950°C
Answer
Answer: c
3. At what temperature does the high carbon steel get forged?
a) 950°C
b) 1510°C
c) 1150°C
d) 1290°C
Answer
Answer: c [Reason:] The high carbon steel is provided heat treatment, after this, the steel is allowed to quench and then tempered. They can be forged at a temperature of 1100°C.
4. At what temperature does alloy steel get forged?
a) 850°C
b) 970°C
c) 1050°C
d) 1200°C
Answer
Answer: a [Reason:] For the improvisation of mechanical and physical properties of the materials, a variety of materials are added and to make it an alloying steel. The temperature at which alloy steel can be forged is in the range of 825°C to 875°C.
5. At what temperature does wrought irons get forged?
a) Below 1000°C
b) Below 1100°C
c) Below 1200°C
d) Below 1300°C
Answer
Answer: d [Reason:] Wrought irons are identified as alloys of iron which contain very low amount of carbon in them. Wrought irons can be forged at a temperature below 1300°C.
6. What is the forging temperature of brass?
a) 450°C
b) 500°C
c) 550°C
d) 600°C
Answer
Answer: d [Reason:] Brass is an alloy of mainly two metals being, copper and zinc. These two metals can substitute each other’s place in the structure of the alloy. The temperature at which brass gets forged is about 600oC.
7. What is the forging temperature of bronze?
a) 850°C
b) 900°C
c) 950°C
d) 1000°C
Answer
Answer: c [Reason:] Bronze is an alloy which essentially contains copper in it and generally is found to contain about 12% of tin. It may also have some other additives in it like, manganese, zinc or nickel. The temperature at which bronze gets forged is about 950°C.
8. What is the forging temperature of magnesium alloys?
a) 450°C
b) 500°C
c) 550°C
d) 600°C
Answer
Answer: b [Reason:] Metals such as zinc, copper, zirconium, silicon or aluminium are mixed with magnesium to form a magnesium alloy. In terms of structure, magnesium is considered to be the lightest metal. The temperature at which magnesium alloys get forged is 500°C.
9. The grain size of steel increases with an increase in temperature.
a) True
b) False
Answer
Answer: a [Reason:] With an increase in the temperature, when the temperature goes above the upper critical temperature limit, the grain size of steel also begins to increase. However on forging, the grain is broken down.
10. Cold working of steel takes place at a temperature below 823°C.
a) True
b) False
Answer
Answer: b [Reason:] If the hammering of steel has to take place under the temperature of 723°C, then this working would be considered as cold working. By doing this, one may expect for the occurrence of small hair cracks.
Set 3
1. What is the open hearth called in which the metal is heated to its plastic state?
a) Roger’s forging
b) Black’s forging
c) Smith’s forging
d) Gold’s forging
Answer
Answer: c [Reason:] The open hearth in which the metal is brought to its plastic state by increasing its temperature is called as Smith’s forging.
2. Which of the following process is done above the recrystallization temperature?
a) Hot forging
b) Cold forging
c) Impact forging
d) Gradual pressure forging
Answer
Answer: a [Reason:] Among hot forging, cold forging, impact forging and gradual pressure forging, hot forging is done above the recrystallization temperature, but below the melting point.
3. Which of the following method is used for manufacturing screws?
a) Hot forging
b) Cold forging
c) Impact forging
d) Gradual pressure forging
Answer
Answer: b [Reason:] For manufacturing of products like screws, pins or nails, the process of hot forging or impact forging is not recommended. But, for this, cold forging is highly used.
4. Which of the following method is used for manufacturing shafts?
a) Open die forging
b) Closed die forging
c) Impact forging
d) Flashless forging
Answer
Answer: a [Reason:] While the manufacture of products like shafts, discs or rings, the method of closed die forging or impact forging or flashless forging is not advised, but open die forging is used.
5. In which of the following process, does the die have a concave surface?
a) Fullering
b) Edging
c) Cogging
d) Cavitising
Answer
Answer: b [Reason:] Among the following processes, that is fullering, edging, cogging and cavitising, edging is a process in which, the die has a concave shape.
6. Cold forging causes reduction in strength of material.
a) True
b) False
Answer
Answer: b [Reason:] Strain hardening is caused by cold forging, whereas hot forging results in reduction of the strength of the material.
7. In which of the following process, does the die have a convex surface?
a) Fullering
b) Edging
c) Cogging
d) Cavitising
Answer
Answer: b
8. Which of the following operation is called incremental forging?
a) Fullering
b) Edging
c) Cogging
d) Cavitising
Answer
Answer: c [Reason:] Among the following process, cogging is the operation in which the surface is contoured a little. This process is also called as incremental forging.
9. Which of the following process is used for making slabs?
a) Fullering
b) Edging
c) Cogging
d) Cavitising
Answer
Answer: Among the following processes, cogging is a process which is used for the manufacturing of processes like blooms and slabs from the cast ingots.
10. The cost of cold dies is high.
a) True
b) False
Answer
Answer: a [Reason:] It is observed that the initial cost of dies in case of cold dies forging is comparatively high. Not just that, but this process is also a little complex one.
Set 4
1. HPF steel is normalized at what temperature?
a) 800°C
b) 900°C
c) 1000°C
d) 1100°C
Answer
Answer: b [Reason:] The HPF steel has to be taken to high magnitudes of temperatures. The HPF steel or the hot press forming steel gets normalized at 900°C.
2. What is the Vickers hardness of steel before the HPF process?
a) 150 Hv
b) 160 Hv
c) 170 Hv
d) 180 Hv
Answer
Answer: c [Reason:] The HPF process in steels is considered to be a very important process, it involves heating the steel to high temperatures. The Vickers hardness of steel before HPF process is 170 Hv.
3. What is the Vickers hardness of steel after the HPF process?
a) 362 Hv
b) 462 Hv
c) 562 Hv
d) 662 Hv
Answer
Answer: b [Reason:] The HPF process is a very essential process. The Vickers hardness of the material is found to change after this process is done. The Vickers hardness of steel after HPF process is 462 Hv.
4. What is the amount of carbon used in HPF steel?
a) Less than 0.37%
b) Less than 0.27%
c) Less than 0.47%
d) Less than 0.57%
Answer
Answer: b [Reason:] The carbon content which is used in HPF steel is very less in percentage composition. The amount of carbon used in terms of percentage weight is less than 0.27%.
5. What is the amount of silicon used in HPF steel?
a) Less than 0.30%
b) Less than 0.20%
c) Less than 0.40%
d) Less than 0.50%
Answer
Answer: d [Reason:] The silicon content which is used in HPF steel is very less in percentage composition. The amount of silicon used in terms of percentage weight is less than 0.50%.
6. What is the amount of boron used in HPF steel?
a) Less than 0.003%
b) Less than 0.007%
c) Less than 0.009%
d) Less than 0.057%
Answer
Answer: a [Reason:] The boron content which is used in HPF steel is extremely less in percentage composition. The amount of boron used in terms of percentage weight is less than 0.003%.
7. What is the amount of tungsten used in HPF steel?
a) Less than 0.03%
b) Less than 0.02%
c) Less than 0.04%
d) Less than 0.05%
Answer
Answer: d [Reason:] The tungsten content which is used in HPF steel is very less in terms of percentage composition. The amount of tungsten used in terms of percentage weight is less than 0.05%.
8. What is the amount of nitrogen used in HPF steel?
a) Less than 0.03%
b) Less than 0.02%
c) Less than 0.04%
d) Less than 0.05%
Answer
Answer: b [Reason:] The nitrogen content which is used in HPF steel is very less in percentage composition. The amount of nitrogen used in terms of percentage weight is less than 0.02%.
9. In an inverse rate curve for steel, steel is heated uniformly.
a) True
b) False
Answer
Answer: a [Reason:] In an inverse rate curve for steel, the steel is not just heated uniformly, also its temperature is recorded.
10. In an HPF steel, amount of manganese used is 3% by weight.
a) True
b) False
Answer
Answer: b [Reason:] The manganese content which is used in HPF steel is comparatively more than other substances in percentage composition. The amount of manganese used for HPF steel is less, approximately about, 1.5% to 2.0%.
Set 5
1. Which of the following material is not used in extrusion?
a) Wax
b) Granules
c) Powder
d) Pellets
Answer
Answer: a [Reason:] Extrusion is a process of forcing plastic which is at a very high temperature, through the dies, and gets opened at a required shape. The raw materials used for extrusion with polymers contains granules, powder and thermoplastic pellets.
2. In extrusion process, extra shearing occurs in which part of the system?
a) Feed section
b) Pumping section
c) Collapse section
d) Transition section
Answer
Answer: b [Reason:] The section where an additional amount of melting and shearing occurs is called as pumping section.
3. Melting section is another name for which section?
a) Feed section
b) Transition section
c) Pumping section
d) Collapse section
Answer
Answer: b [Reason:] Melting section is one of the types of extrusion in polymers. Extrusion is a process of forcing plastic which is at a very high temperature, through the dies, and gets opened at a required shape. Melting section is another name for transition section.
4. How are extruded materials cooled?
a) Water
b) Contact with chilled surface
c) Air
d) Oil
Answer
Answer: d [Reason:] On completion of extrusion, the material is very hot and has to be cooled down. There are various agents which are used cooling these materials down, such as, air or water or its direct contact with a very cold surface.
5. Which of the following is not an important factor of cooling in extrusion?
a) Reduction in shrinkage
b) Reduction in distortion
c) Ease of adding colours
d) Rate of cooling
Answer
Answer: c [Reason:] There are various factors of cooling, a few of them are, reduction in shrinkage, reduction in distortion and the rate of cooling too has to be considered.
6. Which of the following is not an application of polymer extrusion?
a) Door insulation seals
b) Chewing gums
c) Cables
d) Circuit boards
Answer
Answer: d
7. Film extrusion process, best involves film having thickness below what length?
a) 0.2 mm
b) 0.3 mm
c) 0.4 mm
d) 0.5 mm
Answer
Answer: d [Reason:] Extrusion of films is one of the most important processes in extrusion. For the films having thickness below 0.5 mm, these films are best suited for extrusion and can be further applied for making, various bags.
8. In cable extrusion process, what is the speed of product winding?
a) 40 m/sec
b) 50 m/sec
c) 60 m/sec
d) 70 m/sec
Answer
Answer: b [Reason:] For the insulation purpose, the coating of any wire or cable is one of the most vital polymer extrusion process. The wire is cooled and then it is wound to large spools at a speed of 50 meters per second.
9. Calendering is mostly suited for making PVC.
a) True
b) False
Answer
Answer: a [Reason:] Calendering process is considered to be one of the most important sheet forming process. Calendering has many products like phenyl, cellulose or vinyl floor tiles. It is most suited for making PVCs.
10. Tubes having U shape cannot be manufactured by polymer extrusion process.
a) True
b) False
Answer
Answer: b [Reason:] Polymer extrusion has variety of applications such as, candy canes, chewing gums, window frames, solid rods, pipes or tubes having U or J sections.
