Multiple choice question for engineering
Set 1
1. Which of the following components of the X-ray fluorescent spectrometer induces fluorescent radiation?
a) Excitation source
b) Energy analyser
c) X-ray spectrometer
d) Detection System
Answer
Answer: a [Reason:] Excitation source induces fluorescent radiation in X-ray fluorescent spectrometer. A mono-energetic source is required for this purpose.
2. Why is a mono-energetic radiation source required in X-ray fluorescent spectrometer?
a) To provide good sensitivity
b) To provide high accuracy
c) To provide a proper range
d) To reduce unwanted background
Answer
Answer: d [Reason:] Mono-energetic radiation source is required in X-ray fluorescent spectrometer to reduce unwanted background. This occurs due to the scattering occurring over a broad range of wavelengths.
3. Which of the following does not make the X-ray tube nearly monochromatic?
a) Transmission-anode X-ray tube
b) Secondary fluorescence target
c) Slit
d) Filters
Answer
Answer: c [Reason:] Slits do not make the X-ray tube nearly monochromatic. The most commonly used source is X-ray tubes.
4. Which of the following components make use of a thin metal foil to isolate a nearly mono-energetic excitation beam?
a) Transmission-anode X-ray tube
b) Secondary fluorescence target
c) Slit
d) Filters
Answer
Answer: d [Reason:] Filters make use of a thin metal foil to isolate a nearly mono-energetic excitation beam. Nickel is one of the metals that is used in filters.
5. Energy dispersive system uses which of the following detectors?
a) Optical detector
b) Semiconductor detector
c) Thermistor
d) Bolometer
Answer
Answer: b [Reason:] Energy dispersive system uses semiconductor detectors. It consists of an excitation source and a sample.
6. In Energy dispersive system, the energy level and the number of pulses is related to which of the following?
a) Amount of sample, element involved
b) Element involved, concentration of the element
c) Concentration of the element, element involved
d) Number of atoms, amount of sample
Answer
Answer: b [Reason:] In Energy dispersive system, the energy level is related to the element involved. The number of pulses is related to the concentration of the element involved.
7. The analysis of X-ray beam by diffraction is similar to spectrum analysis carried out with a diffraction grating.
a) True
b) False
Answer
Answer: a [Reason:] The analysis of X-ray beam by diffraction is similar to spectrum analysis carried out with a diffraction grating. Wavelength dispersive type of meter derives its name from this fact.
8. The crystal used as X-ray grating has _______ dimensional lattice arrays?
a) One
b) Two
c) Three
d) Four
Answer
Answer: c [Reason:] The crystal used as X-ray grating has three dimensional lattice arrays. Photons can be coherently scattered using the crystals.
9. Which of the following can be done to avoid loss of intensities of X-rays due to absorption of long wavelength X-rays?
a) Apparatus must be contained in a chamber
b) Air in the chamber must be replaced by helium
c) Inert gas atmosphere must be provided
d) Proper slits must be used
Answer
Answer: b [Reason:] Air in the chamber must be replaced by helium to avoid loss of intensities of X-rays due to absorption of long wavelength X-rays. Vacuum chambers can also be used.
10. In curved crystal arrangement, angular velocity of the crystal is twice that of the detector.
a) True
b) False
Answer
Answer: b [Reason:] In curved crystal arrangement, angular velocity of the detector is twice that of the crystal. This arrangement is suitable for the analysis of small specimens.
11. Which of the following is the disadvantage of silicon semiconductor detector?
a) Low stable
b) Can be operated only at low temperatures
c) Have low count-rate
d) Low resolution
Answer
Answer: b [Reason:] The disadvantage of silicon semiconductor detector is that they can be operated only at low temperatures. They have high stability, high count-rate and adequate resolution.
12. Given below is the diagram of energy dispersive system. Identify the unmarked component.
a) Lens
b) Specimen
c) Sample holder
d) Energy analyser
Answer
Answer: b [Reason:] The unmarked component is specimen. This system consists of source, sample and detector.
Set 2
1. In pressure die casting, what is the minimum pressure that can be applied?
a) 50 kg/cm2
b) 60 kg/cm2
c) 70 kg/cm2
d) 80 kg/cm2
Answer
Answer: c [Reason:] The minimum pressure, which can be applied in a pressure die casting is 70 kg/cm2. Below this pressure at 50 or 60kg/cm2, the process of casting will not take place.
2. What is the maximum pressure, which can be applied in a pressure die casting?
a) 4530 kg/cm2
b) 4980 kg/cm2
c) 5000 kg/cm2
d) 5100 kg/cm2
Answer
Answer: c [Reason:] The maximum pressure, which can be applied in a pressure die casting is 5000 kg/cm2. For some castings, with lesser hardness, the maximum pressure limit is lesser. If the magnitude of pressure applied exceeds the value of 5000kg/cm2, then the cast may get damaged.
3. Alloys of which of the following metal is not used for hot chamber die casting?
a) Tin
b) Lead
c) Zinc
d) Iron
Answer
Answer: d [Reason:] Among the following metals, the alloys which are made up of iron are least manufactured using hot chamber die cast method, while all other are widely used.
4. In cold chamber die casting, what is the minimum pressure that can be applied?
a) 140 kg/cm2
b) 180 kg/cm2
c) 150 kg/cm2
d) 200 kg/cm2
Answer
Answer: d [Reason:] In cold chamber die casting, a decent amount of pressure has to be given. The minimum pressure, which can be applied in a cold chamber die casting is 200 kg/cm2.
5. In cold chamber die casting, what is the maximum pressure that can be applied?
a) 500 kg/cm2
b) 1000 kg/cm2
c) 1500 kg/cm2
d) 2000 kg/cm2
Answer
Answer: d
6. In hot chamber die casting, before the end of the stroke, what uncovers the port?
a) Injector
b) Plunger
c) Burning flame
d) Die cavity
Answer
Answer: b [Reason:] In the process of hot chamber die casting, as soon as the stroke ends, there has to be some part which would remove the cover over the port. In hot chamber die casting, before the end of the stroke, it is the plunger that uncovers the port.
7. Which of the following is not counted among the limitations of pressure die casting?
a) Only small parts can be produced
b) High cost
c) Low scale production
d) Castings are porous
Answer
Answer: c [Reason:] Pressure die casting are used for mass production, the reason being, that equipments needed in pressure die casting are not available at low costs. The dies used in this process too are very expensive.
8. Up to what tolerances can pressure die casting be possible?
a) ± 0.067mm
b) ± 0.076mm
c) ± 0.025mm
d) ± 0.052mm
Answer
Answer: b [Reason:] Pressure die casting, overall is a very useful process. It is handy when small parts are to be produced. Up to ± 0.076mm of close tolerance, in pressure die casting, making small parts becomes possible.
9. Up to what thickness can the sections be casted?
a) 0.3mm
b) 0.4mm
c) 0.5mm
d) 0.6mm
Answer
Answer: c [Reason:] In pressure die casting, it is one of the advantages of this process, that castings which have a very small sections too can be casted by it. The section of the casts can be manufactured up to 0.5mm.
10. In pressure die castings, production rate is low?
a) True
b) False
Answer
Answer: b [Reason:] In pressure die castings, a very high production rate is possible, as it becomes economical for large quantities.
Set 3
1. Presence of which material in aluminium alloy provides ductility to the alloy?
a) Silicon
b) Iron
c) Copper
d) Zinc
Answer
Answer: c [Reason:] With the presence of about 2% to 5% of copper metal in aluminium alloy aids in the increase in ductility of the alloy, that is, it becomes easy for the alloy to be stretched into wires.
2. Which furnace is not used for heating aluminium alloys?
a) Electric arc furnace
b) Pot furnace
c) Induction heating furnace
d) Crucible furnace
Answer
Answer: a [Reason:] Aluminium alloys can be melted or heated directly or indirectly by fuel firing furnace. The heating can take place in a pot furnace, induction heating furnace, a crucible furnace or a reverberatory furnace.
3. Which of the following is not a purpose of fluxing and flushing the aluminium alloys?
a) Removal of dissolved hydrogen
b) Removal of dissolved oxygen
c) Separation of dross from melt
d) Entrapment of dross
Answer
Answer: b [Reason:] Fluxing and flushing are an important task in aluminium alloy foundries. It is done for removing the dissolved hydrogen from the melt, for separating the dross from molten metal and to entrap the dross.
4. What is the silicon composition present in an LM-17 cast aluminium alloy?
a) 3%
b) 12%
c) 5.5%
d) 11.5%
Answer
Answer: d [Reason:] In an LM-1 cast aluminium alloy, silicon content is 3%. In an LM-13 cast aluminium alloy, silicon content is 12%. In an LM-8 cast aluminium alloy, silicon content is 5.5% and in an LM-17 cast aluminium alloy, the silicon content is 11.5%.
5. Which gas is not used for fluxing and flushing in aluminium alloys?
a) Argon
b) Chlorine
c) Nitrogen
d) Oxygen
Answer
Answer: d [Reason:] Fluxing and flushing is an operation which is done for the removal of hydrogen from the molten metal. In this process, argon gas, chlorine gas, nitrogen gas and helium gas are used as fluxes and not oxygen.
6. Up to what length can the surface finish be achieved by green sand in aluminium alloys?
a) 600 micro inch
b) 650 micro inch
c) 700 micro inch
d) 750 micro inch
Answer
Answer: b [Reason:] When green sand is used for molding in aluminium alloys, the surface finish can be achieved from about 300 micro inch to 650 micro inch, which is about 7500 micro mm to 16,250 micro mm.
7. Which of the given metals is not counted among late additions in aluminium alloys?
a) Boron
b) Titanium
c) Manganese
d) Sodium
Answer
Answer: c [Reason:] There are certain metals which are added very late in the molten cast. By doing this, aluminium alloys get refined. A few of those metals are, boron, titanium, sodium, chromium and columbium. Manganese is added in aluminium during the operation, not late.
8. Aluminium alloys are not susceptible to which of the following?
a) Macro shrinkage
b) Drossing
c) Micro shrinkage
d) Solidification shrinkage
Answer
Answer: a [Reason:] Aluminium alloys are susceptible to drossing, micro shrinkages and solidification shrinkages, but not to macro shrinkages. For prevention of entering of dross in mold cavity, gating system is installed.
9. A runner is located away from the drag.
a) True
b) False
Answer
Answer: b [Reason:] A runner has to be located in the drag. The area of the runner should be small and ideally equal to the ingate area. It should be streamlined to avoid turbulence.
10. Pouring basins are used for reducing vortex formation.
a) True
b) False
Answer
Answer: a [Reason:] The design made for pouring basins in the working of aluminium alloys, is purposed for the reduction of turbulence and vortex formation. It also aids in the reduction of mechanical washing of dross.
Set 4
1. In blow molding, to inflate soft plastic, which medium is used?
a) Air
b) Water
c) Oil
d) Alcohol
Answer
Answer: a [Reason:] Blow molding process is typically used for the blowing process of hollow plastics. While blow molding, the plastic has to be inflated, in order to do so, air has to be blown inside with a high amount of pressure.
2. Which of the following plastics is not used in blow molding?
a) Terephthalate
b) Polypropylene
c) Polythene
d) PVC
Answer
Answer: a [Reason:] For blowing processes, there are certain plastics only which are properly suited for the operation, while any other material might fail. Hence, for operating through blow molding process, polypropylene, polythene and PVC are used.
3. What is the minimum air pressure required in blow molding process?
a) 350 kPa
b) 400 kPa
c) 450 kPa
d) 500 kPa
Answer
Answer: b [Reason:] In blow molding process, there is some amount of pressure that has to be given to the air for blowing the bottles. The amount of pressure to be given depends on the material. The minimum pressure that can be given in this process is 400 kPa.
4. What can be the maximum pressure to be given to a plastic for blow molding process?
a) 700 kPa
b) 750 kPa
c) 800 kPa
d) 850 kPa
Answer
Answer: c [Reason:] Air with an extreme amount of pressure, when is needed, it might mean the material is thicker and denser. The amount of pressure that can be provided depends totally on the material. The maximum pressure that can be provided in blow molding process is 800 kPa.
5. Which of the following is not a type of blow molding process?
a) Injection blow molding
b) Extrusion blow molding
c) Multi-smaller blow molding
d) Multi-larger blow molding
Answer
Answer: c [Reason:] Blow molding basically is a process of inflation of air under pressure into the plastics inside the mold cavity. There are only three known types of blow molding, namely, injection blow molding, extrusion blow molding and multi larger blow molding.
6. What is the minimum thickness required by the plastic for vacuum forming?
a) 0.125 mm
b) 0.25 mm
c) 0.375 mm
d) 0.5 mm
Answer
Answer: a [Reason:] Vacuum forming is one of the classifications of thermoforming processes. Around its circumference, a clamp is attached or which we need to know the minimum thickness. The minimum thickness that can be allowed for this operation is 0.125 mm.
7. Which of the following is not an application of blow molding process?
a) Toy bodies
b) Door liners
c) Bottles
d) Pipes
Answer
Answer: b [Reason:] Among the following, only door liners is not an application of blow molding process. Internal door liners are made using thermoforming process, while toy bodies, bottles and pipes are made using blow molding process.
8. What is the maximum thickness that can be allowed for a plastics sheet in vacuum forming process?
a) 3 mm
b) 3.1 mm
c) 3.2 mm
d) 3.3 mm
Answer
Answer: c [Reason:] Vacuum forming process is one of the important processes that are employed in thermoforming processes. The maximum thickness of the plastic sheet has to be noted, as a clamp is to be fitted around the plastic sheet. The maximum allowable thickness of this plastic sheet is 3.2mm.
9. The heater in vacuum forming process is heated up to 90°C.
a) True
b) False
Answer
Answer: a [Reason:] In vacuum forming process, there is a clamp which has to be used for holding the plastic sheets. There is a heater employed for heating the mold cavity. The heater brings the polymer in a temperature range of 55°C to 90°C.
10. The initial cost in blow molding is low.
a) True
b) False
Answer
Answer: a [Reason:] In blow molding, there is a mold cavity present inside the soft plastic, into which, the air with high amount of pressure has to be blown. The capital required for mold initially is quite less, making it a little inexpensive process.
Set 5
1. Which of the following is not a bonding theory?
a) Electrostatic bonding theory
b) Hot strength theory
c) Surface tension theory
d) Block and wedge theory
Answer
Answer: b [Reason:] Hot strength theory is not one of the bonding theories, while electrostatic theory, surface tension theory and block and wedge theory are bonding theories.
2. In which of the following bonding theory, water molecules break down to form H+ and OH- ions?
a) Electrostatic bonding theory
b) Hot strength theory
c) Surface tension theory
d) Block and wedge theory
Answer
Answer: a [Reason:] In electrostatic bonding theory, water is mixed in clay and sand grains, these water molecules then break into H+ ions and OH– ions.
3. What does the clay particle absorb in electrostatic bonding theory?
a) Complete water
b) H+ ions
c) OH–ions
d) Sand grains
Answer
Answer: c [Reason:] The OH– ions are basically the base ions. The clay particles in electrostatic bonding theory, absorb the OH– ions because of the not satisfied valence bond.
4. For bonding action of clays, what is the amount of water needed?
a) 1.5%-8%
b) 3.5%-11%
c) 4.5%-12%
d) 5.5%-13%
Answer
Answer: a [Reason:] For the bonding action of the clays, water is needed, which activates the sand and clay-sand mixture. The amount needed for this is 1.5% to 8%.
5. What is the amount of sea coal needed in cast irons for small casting moulding sands?
a) 1%
b) 2%
c) 3%
d) 4%
Answer
Answer: a [Reason:] In bonding of substances, an extremely small quantity of sea coal is also needed. Sea coal is used for surface appearance improvement. It is used about 1% in cast iron moulding sands for small castings.
6. What is the amount of sea coal needed in cast irons for large green casting moulding sands?
a) 10%
b) 15%
c) 20%
d) 25%
Answer
Answer: a [Reason:] Sea coal otherwise is used in small numbers for binding. Sea coal is used for surface appearance improvement. It is used about 10% in cast iron moulding sands for large green casting sands.
7. At what temperature is pitch distilled from soft coals?
a) 400°F
b) 500°F
c) 600°F
d) 700°F
Answer
Answer: c [Reason:] For pitch distillation of soft coals, a decently high temperature level has to be attained. From soft coal, pitch is distilled at a temperature of around 600°F and a by-product called Asphalt is produced.
8. Pitch maybe used up to what percent?
a) 1%
b) 2%
c) 3%
d) 4%
Answer
Answer: b [Reason:] Pitch distillation of soft coals plays a vital role in bonding theory. Pitch is used for getting a good surface finish on iron casts. These pitches generally are used up to be to 2%.
9. Which of the following increases dry strength of the sand?
a) Iron oxides
b) Fuel oils
c) Cereals
d) Dextrin and molasses
Answer
Answer: d [Reason:] Dextrin and molasses are used for increasing the dry strength of the sand, which add hardness to the mould.
10. Cereals improve flowability and lowers collapsibility.
a) True
b) False
Answer
Answer: b [Reason:] Cereals do not improve flowability, as a matter of fact it reduces it, and, cereals are not known to reduce or not the collapsibility, in fact it is known to improve it.
11. How much should fuel oil be added to increase the moulding ability of sand?
a) 0.01% – 0.1%
b) 0.02% – 0.2%
c) 0.03% – 0.3%
d) 0.04% – 0.4%
Answer
Answer: a [Reason:] Fuel oils are known to have great properties in them. Fuel oils are helpful in adding to the increase of the moulding ability of sand. It can be added in the range of 0.01% to 0.1%.