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Showing posts with label Material Science. Show all posts
Showing posts with label Material Science. Show all posts

Wednesday, February 12, 2020

FERROUS & NON - FERROUS ALLOYS SET 08
February 12, 2020

FERROUS & NON - FERROUS ALLOYS SET 08

FERROUS & NON - FERROUS ALLOYS SET 08

1. Teflon resin coating can be used to increase the lubricity of magnesium alloys.
a) True
b) False
 
Answer: a
 
Explanation: Teflon resin is a low cost coating which is primarily used for magnesium alloys to improve corrosion resistant properties. It is a chromium free corrosion resistant coating that can be also used for improving lubricity and frictional resistance. It also includes non-wetting features which keeps the casting moisture free.
 
2. Presence of which material in aluminium alloy provides ductility to the alloy?
a) Silicon
b) Iron
c) Copper
d) Zinc
 
Answer: c
 
Explanation: 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.
 
3. Which furnace is not used for heating aluminium alloys?
a) Electric arc furnace
b) Pot furnace
c) Induction heating furnace
d) Crucible furnace
 
Answer: a
 
Explanation: 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.
 
4. 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: b
 
Explanation: 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.
 
5. What is the silicon composition present in an LM-17 cast aluminium alloy?
a) 3%
b) 12%
c) 5.5%
d) 11.5%
 
Answer: d
 
Explanation: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%.
 
6. Which gas is not used for fluxing and flushing in aluminium alloys?
a) Argon
b) Chlorine
c) Nitrogen
d) Oxygen
 
Answer: d
 
Explanation: 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.
 
7. 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: b
 
Explanation: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.
 
8. Which of the given metals is not counted among late additions in aluminium alloys?
a) Boron
b) Titanium
c) Manganese
d) Sodium
 
Answer: c
 
Explanation: 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.
 
9. Aluminium alloys are not susceptible to which of the following?
a) Macro shrinkage
b) Drossing
c) Micro shrinkage
d) Solidification shrinkage
 
Answer: a
 
Explanation:Aluminium alloys are susceptible to drossing, micro shrinkages and solidification shrinkages, but not to macro shrinkages. For the prevention of entering of dross in mold cavity, gating system is installed.
 
10. A runner is located away from the drag.
a) True
b) False
 
Answer: b
 
Explanation: 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.
 
11. Pouring basins are used for reducing vortex formation.
a) True
b) False
 
Answer: a
 
Explanation: 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.


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FERROUS & NON - FERROUS ALLOYS SET 07
February 12, 2020

FERROUS & NON - FERROUS ALLOYS SET 07

FERROUS & NON - FERROUS ALLOYS SET 07

1. In sand casting of magnesium alloys, what is the amount of bentonite sand used in a British mix?
a) 3 lb
b) 4 lb
c) 5 lb
d) 6 lb
 
Answer: b
 
Explanation:In the production of magnesium alloys, there are a variety of sands employed. For this, bentonite sand has to be used for the sand casting of the alloys. The amount of bentonite sand used is 4 lbs in both British as well as American mix.
 
2. In general, magnesium alloy components tends to have fine grain structure in it.
a) True
b) False
 
Answer: b
 
Explanation: In general, magnesium alloy component tends to have coarse grain structure unless some suitable procedures are taken to insure the formation of fine grains. The procedure involves superheating of molten metal to 2500 or 3000 ⁰C. And then after holding it there for a certain period of time, it cools down to the desired temperature and pouring operation takes place without any delay.
 
3. Magnesium is a very light material that can be suitable in aircraft applications.
a) True
b) False
 
Answer: a
 
Explanation: Magnesium is very light metal in comparison with other structural metals. Magnesium is commonly used in a wide range of markets and applications, from automobiles to aircraft applications. In most of the cases of manufacturing, weight reducing is the primary objective for magnesium alloys.
 
4. Magnesium metal is very light material, but not lighter than aluminium metal.
a) True
b) False
 
Answer: b
 
Explanation: Magnesium is mainly distinguished by its low density, which is nearly about 25% of steel and about 60% of the aluminium metal. This property makes magnesium to use for very lightweight construction. In expensive cars, it is highly used in the construction of crankcase and in other parts to increase power to weight ratio.
 
5. Magnesium cannot be used extensively for precision casting applications.
a) True
b) False
 
Answer: a
 
Explanation: Magnesium cannot be used extensively for precision casting applications because it is highly reactive with silica containing constituents like plaster or other mould materials. Silica is mostly present in slurry in which it acts like binding material. Reaction of magnesium with silica produces magnesium oxide and magnesium silicide which may imparts defects in the casting components.
 
6. Adding of zirconium in magnesium metal results in the formation of magnesium-zirconium alloy of enhanced ductility.
a) True
b) False
 
Answer: b
 
Explanation: The grain size is highly affected by adding zirconium in magnesium metal. Addition of less than 0.6% zirconium in magnesium is sufficient to obtain grain size less than 80 microns in casted components. This further increases hardness in the material due to formation of fine grains and ductility also decreases simultaneously.
 
7. Inhibitors are generally used in mould to avoid reaction of magnesium with moulding materials.
a) True
b) False
 
Answer: a
 
Explanation: When moulding materials like silica, moisture and binders make contact with magnesium, the reaction takes place which arise problems in the castings of magnesium alloys. To avoid reaction, the mould is modified by using some techniques like drying and by including inhibitors in the moulding materials.
 
8. Which of the following compounds can be used as an inhibitor in moulding materials for avoiding chemical reaction with magnesium alloys?
a) Sodium silicate
b) Water
c) Hydrogen silicate
d) Potassium borofluoride
 
Answer: d
 
Explanation: Moulding materials are effectively inhibited by adding 1 to 2 percent of potassium borofluoride. And controlling of inhibitor content in moulding materials is very important because they can affect setting times. Sometimes elimination of silica content from moulding materials also takes place to avoid chemical reactions.
 
9. Magnesium metal possesses better noise and vibration damping characteristics than aluminum.
a) True
b) False
 
Answer: a
 
Explanation: Magnesium is the lightest material in all the engineering materials. It has good ductility, better noise and vibration damping features than aluminium and also has excellent cast-ability. Alloying of magnesium metal with aluminium, manganese increases the strength of the components and also reduces the weight of the casted parts, so magnesium alloys are very important materials for applications where weight saving is a dominant objective.
 
10. Magnesium alloys do not require any special coating as they are self protective from corrosion.
a) True
b) False
 
Answer: b
 
Explanation: Different types of coatings are applied to magnesium alloys to increase corrosion resistance. Coatings for magnesium alloys are applied by using hexavalent chromium material which provides excellent protection, but do not considered as eco-friendly. To avoid environmental problems, Teflon resin is basically applied instead of any other coatings.
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FERROUS & NON - FERROUS ALLOYS SET 06
February 12, 2020

FERROUS & NON - FERROUS ALLOYS SET 06

FERROUS & NON - FERROUS ALLOYS SET 06

1. Which of the following metals is least used in making magnesium alloys?
a) Aluminium
b) Zinc
c) Copper
d) Manganese
 
Answer: c
 
Explanation: Magnesium metal in itself is not one of the strongest metals and is hence adulterated with other materials to form strong alloys. Among the following, aluminium, zinc and manganese are highly used in making magnesium alloys.
 
2. Which of the following can be the casting temperature for magnesium alloys?
a) 630°C
b) 760°C
c) 850°C
d) 970°C
 
Answer: b
 
Explanation: When it comes to casting of magnesium alloys, the casting temperatures have to be kept in real control, that is, if the temperatures go too high, the metal might catch fire. The temperature range for casting magnesium alloys is 720°C to 800°C.
 
3. Which of the following is not a property of a magnesium alloy?
a) High damping capacity
b) High electrical conductivity
c) Good fatigue strength
d) High thermal resistivity
 
Answer: d
 
Explanation: Magnesium on getting mixed with other elements starts possessing many different properties. It contains good damping capacity, good electrical conductivity and good fatigue strength, but not, thermal resistivity.
 
4. What is the color of pure magnesium metal?
a) Red
b) White
c) Black
d) Yellow
 
Answer: b
 
Explanation: The purest form of magnesium is considered to be in its weakest form, and hence other elements are added in it to enhance its quality. The physical qualities too change on addition of other elements. Originally, the color of pure magnesium metal is silvery white.
 
5. What should be the temperature of the mixture while alloying takes place?
a) 550°C
b) 600°C
c) 650°C
d) 700°C
 
Answer: d
 
Explanation: During the mixture getting processed, first the magnesium is melted, and then zinc metal is added. Aluminum is mixed in it through stirring. While this is happening, it has to be ensured, that the complete alloying process takes place at 700°C.
 
6. In magnesium alloys, what is the maximum amount of allowed aluminum?
a) 11%
b) 13%
c) 19%
d) 24%
 
Answer: a
 
Explanation: Magnesium alloys are basically a composition of various metals mixed with magnesium to improve its physical, chemical, mechanical and thermal properties. In this, the maximum allowable aluminum that can be added is only 11%.
 
7. What should the temperature ideally be to remove the casting after making of magnesium alloys?
a) Below 450°C
b) Below 300°C
c) Below 350°C
d) Below 300°C
 
Answer: d
 
Explanation: It is always advisable that the castings should never be removed too quickly, as it might lead to distortion of the cast because it is still hot. Therefore, when the temperature of the cast is below 300°C, the magnesium alloy cast can be removed.
 
8. In grain refinement process, only hexachlorobenzene is used.
a) True
b) False
 
Answer: b
 
Explanation: In grain refinement process, there is another process called carbon inoculation, in which, tablets of organic compounds are used, namely hexachlorobenzene and hexachloroethane.
 
9. Magnesium alloys have a low strength to weight ratio.
a) True
b) False
 
Answer: b
 
Explanation: Magnesium alloys possess many desirable mechanical, physical and thermal properties, which may help in better casting processes. One of these properties is a high strength to weight ratio.
 
10. In sand casting of magnesium alloys, what is the amount of silica sand used in an American mix?
a) 80 lb
b) 90 lb
c) 100 lb
d) 110 lb
 
Answer: c
 
Explanation: It is mainly observed that magnesium alloys are manufactured with the help of sand molds only. The amount of silica sand used in magnesium alloys is 100 lbs in both the British mix and the American mix.
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FERROUS & NON - FERROUS ALLOYS SET 05
February 12, 2020

FERROUS & NON - FERROUS ALLOYS SET 05

FERROUS & NON - FERROUS ALLOYS SET 05

1. Which of the following parts are mostly manufactured by using copper alloys?
a) Pistons
b) Engine blocks
c) Journal bearings
d) Aircrafts
 
Answer: c
 
Explanation: In the manufacturing of journal and other types of solid bearings, copper alloys are mostly preferred. Many other components like worm wheels, gear selector forks and electricity wires are also made by using copper alloys; it is mostly preferred where low friction and high wear resistance is required.
 
2. Copper alloys generally have sparking nature due to its high ductility.
a) True
b) False
 
Answer: b
 
Explanation: Copper alloys components are generally of non-sparking nature, that’s why they are preferred in manufacturing of electrical equipment and components where there is a chance of fire hazard. And the ductile nature of copper alloys is totally independent to its non-sparking nature.
 
3. Copper alloys have low thermal conductivity but high electrical conductivity.
a) True
b) False
 
Answer: b
 
Explanation: Copper alloys have high thermal conductivity as well as high electrical conductivity. Due to high electrical conductivity, they are used in making of electric wires, in motor winding etc. And high thermal conductivity of copper alloys useful in making of heat exchangers, in piping of power-plants, air conditioning, refrigerators etc.
 
4. Copper alloys possess good mechanical properties even at high temperatures.
a) True
b) False
 
Answer: a
 
Explanation: Copper and its alloys have an optimized combination of tensile and compressive strength, hardness, ductility and resistance to shock load to use for various applications. And the mechanical properties of copper alloys at high temperatures are even better than the other non-ferrous materials.
 
5. At zero level temperature of copper alloys, they become very hard and brittle in nature.
a) True
b) False
 
Answer: b
 
Explanation: At zero level temperature of copper alloy castings, no any kind of embrittlement occurs; in fact, the tensile strength of copper castings enhances at low temperature. Therefore, the copper castings can be used at very low temperatures without any significant changes to the properties of the castings.
 
6. Castings or components of copper alloys have high machinability and recyclability.
a) True
b) False
 
Answer: a
 
Explanation: Many alloys consist of lead to increase machinability with easy chip formation. But, copper components itself have excellent machinability. And copper alloy castings are recyclable too, the scrapes of copper alloys castings can be melted and can be used again in the manufacturing of other copper parts.
 
7. In general, copper is highly reactive with sulphur and its chemical compounds.
a) True
b) False
 
Answer: a
 
Explanation: Copper may resists the oxidation, but it is highly reactive with sulphur and its chemical compounds, it produces copper sulphide during the reaction which can be unpleasant for the casting components. The main copper contaminants significantly are phosphorous and iron besides oxygen.
 
8. Copper is generally a polymorphous material with body centered cubic (BCC) lattice structure.
a) True
b) False
 
Answer: b
 
Explanation:Copper is a non-polymorphous material with face centered cubic (FCC) structure. The FCC structure is the only reason for ductility in the copper material. Pure copper is generally reddish in color, and addition of zinc produces the yellow color of the copper and nickel produces the silver color of the same.
 
9. It is very difficult to cast pure copper metal in mould cavity because of shrinkage problems.
a) True
b) False
 
Answer: a
 
Explanation: It is very difficult to cast pure copper in mould cavity because very large shrinkages occur during the solidification of castings, and a large amount of gasses are trapped in the casting at high temperatures which results in the melted material gassing and the porosity in casting components.
 
10. Pure magnesium melts at what temperature?
a) 600°C
b) 650°C
c) 700°C
d) 750°C
 
Answer: b
 
Explanation: The temperature at which the pure form of magnesium gets ignited by itself is 473°C, and the temperature at which magnesium in its purest form is found to melt is 650°C.
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FERROUS & NON - FERROUS ALLOYS SET 04
February 12, 2020

FERROUS & NON - FERROUS ALLOYS SET 04

FERROUS & NON - FERROUS ALLOYS SET 04

1. What is the density of copper alloys?
a) 6.67 g/cc
b) 7.87 g/cc
c) 8.93 g/cc
d) 5.77 g/cc
 
Answer: c
 
Explanation: A steel is a mixture of iron and carbon and copper alloys are mixtures of mainly copper and a few other materials like zinc and nickel with it. The main copper alloys can be brass and bronze. The density of copper alloys in general is found to be 8.93 g/cc.
 
2. Which colour is obtained by copper alloys, when zinc is added to it?
a) Red
b) Blue
c) Silver
d) Yellow
 
Answer: d
 
Explanation: It is one of the most unusual properties of copper alloys, that on addition of different materials in them, there is a change observed in its appearance, that is, the colour of the mixture starts changing. On addition of zinc metal in copper, the colour of the mixture changes to yellow.
 
3. Which colour is obtained by copper alloys, when nickel is added to it?
a) Red
b) Blue
c) Silver
d) Yellow
 
Answer: c
 
4. What amount of impurity is allowed for copper to be used in electric applications?
a) 0.1%
b) 0.2%
c) 0.3%
d) 0.4%
 
Answer: a
 
Explanation: Copper and its alloys find themselves a variety of applications in the field of electrical and micro electrical works. For copper to be able to get used in electric appliances, the maximum impurity that can be allowed is 0.1%.
 
5. Which of the following materials, on adding with copper, doesn’t increase its strength?
a) Cadmium
b) Silver
c) Sodium
d) Aluminium Oxide
 
Answer: c
 
Explanation: Copper originally does not possess a very high amount of strength. For properties of copper to be used, but with more strength, this copper needs to be mixed with certain material, which will provide it the required strength. Cadmium, silver and aluminium oxide are few of those materials which will aid in increasing its strength.
 
6. What is the tensile strength of cast manganese bronze?
a) 490 MPa
b) 759 MPa
c) 676 MPa
d) 324 MPa
 
Answer: a
 
Explanation: 759 mega pascals is the tensile strength of quenched and tempered copper-aluminium alloy. 676 MPa is the tensile strength of cold worked zinc. 324 MPa is the tensile strength of annealed zinc and 490 MPa is the tensile strength of cast manganese bronze.
 
7. What is the tensile strength of pure annealed copper?
a) 324 MPa
b) 676 MPa
c) 759 MPa
d) 209 MPa
 
Answer: d 

8. Copper alloys are mostly hot treated?
a) True
b) False
 
Answer: b
 
Explanation: For properties of copper to be used, but with more strength, this copper needs to be mixed with certain material, which will provide it the required strength. Cadmium, silver and aluminium oxide are few of those materials which will aid in increasing its strength. This process of increasing strength is done by treating the alloy through cold working.
 
9. Iron needs higher temperature ranges for its extraction.
a) True
b) False
 
Answer: a
 
Explanation:The metal copper has its occurrence in large quantities. This material can be successfully extracted from the mines before the iron is extracted, the reason being, copper extraction happens at lower temperatures.
 
10. For protection of copper alloys from corrosion, a special type of coating is applied on it.
a) True
b) False
 
Answer: b
 
Explanation: No any special protective treatments are required for copper alloys against corrosion, as they have capability to protect themselves from corrosion. For the sea water applications, copper alloys are used which have high resistance to corrosion and chloride which is present in sea water in an abundant amount.
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FERROUS & NON - FERROUS ALLOYS SET 03
February 12, 2020

FERROUS & NON - FERROUS ALLOYS SET 03

FERROUS & NON - FERROUS ALLOYS SET 03

1. Alloy of Ni and Fe is known as :
a) Brass
b) Bronze
c) Duralium
d) Invar
 
Answer: d
 
Explanation: Invar contains 36% nickel and 64% iron. Invar is the alloy of Nickel and iron. It has the property of good hardness.
 
2. Major constituent of the gun metal alloy is :
a) Copper
b) Nickel
c) Iron
d) Zinc
 
Answer: a
 
Explanation: Gun metal contains 83% copper and 2% zinc and 10% tin. Gun metal is alloy of copper, zinc and tin, where copper is the base metal.
 
3. Major constituent of Mutz metal alloy is :
a) Copper
b) Nickel
c) Iron
d) Zinc
 
Answer: a
 
Explanation: Mutz metal contains 60% copper and 40% zinc. Mutz metal is the alloy of copper and zinc, where copper is the base metal.
 
4. Major constituent of Nichrome alloy is :
a) Copper
b) Nickel
c) Iron
d) Zinc
 
Answer: b
 
Explanation: Nichrome contains 80% nickel and 20% chromium. Nichrome is the alloy of nickel and chromium where nickel is the base metal.
 
5. Major constituent of Constantan alloy is :
a) Copper
b) Nickel
c) Iron
d) Zinc
 
Answer: a
 
Explanation: Constantan contains 60% copper and 40% nickel. Constantan is the alloy of copper and nickel, where copper is the base metal.
 
6. Major constituent of Elektron alloy is :
a) Copper
b) Nickel
c) Magnesium
d) Zinc
 
Answer: c
 
Explanation: Elektron contains 3-12% aluminum and 2% zinc, 0.03% manganese and rest is magnesium. It is very light alloy and used where weight is the major consideration in design.
 
7. Which of the following alloy is widely used in thermo couples?
a) Brass
b) Bronze
c) Duralium
d) Nichrome
 
Answer: d
 
Explanation: Nichrome contains 80% nickel and 20% chromium and used in thermo couples and strain gauges. Nichrome is a good resistance material to electricity.
 
8. Major constituent of Duralium alloy is :
a) Copper
b) Nickel
c) Iron
d) Aluminum
 
Answer: d
 
Explanation: Aluminum is the major constituent of Duralium alloy. Duralium is very light alloy and used where weight is the major consideration of design.
 
9. What is the approximate percentage of Lead in soft solder?
a) 60
b) 50
c) 90
d) 99.02
 
Answer: b
 
Explanation:Soft solder contains 50% lead and 50% tin. It is used in a fabrication process of two material at a temperature below 450 degree centigrade.
 
10. What is the general density of steel?
a) 6.67 g/cc
b) 7.87 g/cc
c) 8.77 g/cc
d) 5.77 g/cc
 
Answer: b
 
Explanation: A steel is basically a mixture of iron and carbon. The composition of iron varies according to the alloy, high alloy steels contain more amounts of carbon and low alloy steels contain less amount of carbon. The density of steels in general is found to be 7.87 g/cc.
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FERROUS & NON - FERROUS ALLOYS SET 02
February 12, 2020

FERROUS & NON - FERROUS ALLOYS SET 02

FERROUS & NON - FERROUS ALLOYS SET 02

1. Cast iron can be easily obtained in:
a) Cupola
b) Bessemer converter
c) Open hearth furnace
d) Blast furnace
 
Answer: a
 
Explanation: Iron from its pig iron form is converted to cast iron in a cupola. As pig iron is very weak in strength hence it can not be used for practical purpose.
 
2. Wrought iron can be easily obtained by processing iron ore in:
a) Cupola
b) Bessemer converter
c) Pudding furnace
d) Blast furnace
 
Answer: c
 
Explanation: Iron from its pig iron form is converted to wrought iron in pudding furnace. As pig iron is very weak in strength hence it cannot be used for practical purpose.
 
3. Steel can be easily obtained in:
a) Cupola
b) Blast furnace
c) Pudding furnace
d) Bessemer converter
 
Answer: d 
Explanation: Iron from its pig iron form is converted to steel in Bessemer converter.As pig iron is very weak in strength hence it can not be used for practical purpose.
 
4. Red hardness of an alloy steel can be improved using
a) Tungsten
b) Vanadium
c) Manganese
d) Titanium
 
Answer: a
 
Explanation: Red hardness means capability of material to retain hardness at high temperature. Tungsten has a very high melting point and is used to improve red hardness.
 
5. Abrasion resistance of an alloy steel can be improved using
a) Tungsten
b) Vanadium
c) Manganese
d) Titanium
 
Answer: d
 
Explanation: Titanium has very high abrasive resistance property. Titanium is used to improve abrasive resistance of base metal in an alloy.
 
6. Wear resistance of an alloy steel can be improved using
a) Tungsten
b) Vanadium
c) Manganese
d) Titanium
 
Answer: c
 
Explanation: Manganese has very high wear resistance property. Magnesium is alloyed with base metal to increase its wear resistance property.
 
7. Corrosion resistance of an alloy steel can be improved using
a) Tungsten
b) Vanadium
c) Chromium
d) Titanium
 
Answer: c
 
Explanation: Chromium has very high corrosion and oxidation resistance property. Chromium is alloyed with base metal to increase its corrosion resistance.
 
8. Tensile strength of an alloy steel can be improved using
a) Nickel
b) Vanadium
c) Manganese
d) Titanium
 
Answer: a
 
Explanation: Nickel can improve tensile strength as well as toughness of alloy steel. It is alloyed with base metal in small quantity.
 
9. Which of the following induces fine grain distribution in alloy steel?
a) Nickel
b) Vanadium
c) Manganese
d) Titanium
 
Answer: b
 
Explanation: Vanadium induces fine grain distribution in alloy steel. It helps in improving uniformity in the base metal.
 
10. Alloy of copper and zinc is known as :
a) Brass
b) Bronze
c) Duralium
d) Nichrome
 
Answer: a
 
Explanation: Brass contains 50% copper and 50% zinc. Brass is the alloy of copper and zinc. It has good property of corrosion resistance.
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FERROUS & NON - FERROUS ALLOYS SET 01
February 12, 2020

FERROUS & NON - FERROUS ALLOYS SET 01

FERROUS & NON - FERROUS ALLOYS SET 01

1. Which of the metal if present will make the alloy ferrous?
a) Aluminium
b) Lead
c) Zinc
d) Iron
 
Answer: d
 
Explanation: Ferrous metals are metals or alloys which contain iron as an element in it. Therefore Iron is the only ferrous metal among the given options presence of which will make the alloy ferrous.
 
2. Which of the following is costliest among the non ferrous materials?
a) Magnesium
b) Aluminum
c) Titanium
d) Copper
 
Answer: c
 
Explanation: Titanium is the costlier than magnesium, aluminum and copper. This is why titanium has limited application even though it has strength to weight ratio and corrosion resistance.
 
3. Which of the following is the lightest among the following?
a) Magnesium
b) Aluminum
c) Titanium
d) Copper
 
Answer: b
 
Explanation: Aluminum is the lightest among magnesium, titanium and copper. As it is light, it is used at a variety of places.
 
4. Which of the following element when alloyed with magnesium does not reduce the tendency to crack under stress?
a) Aluminum
b) Silicon
c) Zinc
d) Copper
 
Answer: d
 
Explanation: The correct answer is copper. Aluminum, silicon and zinc are alloyed with magnesium to reduce the tendency of magnesium to crack under stress.
 
5. Which of the following is an alloy of tin?
a) Brass
b) Bronze
c) Pewter
d) Steel
 
Answer: c
 
Explanation: Pewter is an alloy of 85 % – 99 % of tin with alloying elements like copper and lead traces.
 
6. Which of the metal is alloyed with silver to make sterling silver?
a) ZInc
b) Copper
c) Magnesium
d) Aluminum
 
Answer: b
 
Explanation: Sterling silver is an alloy of silver to reduce its cost. It is an alloy with 90% of silver and 10% copper.
 
7. Tin has low viscosity.
a) True
b) False
 
Answer: a
 
Explanation: The above statement is true. Tin has low viscosity and therefore is a good material for casting application.
 
8. Which of the following is highly resistant to corrosion?
a) Aluminum
b) Copper
c) Iron
d) Zinc
 
Answer: d
 
Explanation: Zinc is an element which is highly resistant to corrosion therefore it is used as an alloying material to form corrosion resistant alloys. It is also used in galvanization.
 
9. Monel is an alloy of nickel.
a) True
b) False
 
Answer: a
 
Explanation: The above statement is true. Monel is an alloy in which major element is nickel in which copper is added. Magnesium and iron can be added with a limit of 2% and 2.5 % respectively.
 
10. Pig iron can be easily obtained by processing of iron ore in:
a) Cupola
b) Bessemer converter
c) Open hearth furnace
d) Blast furnace
 
Answer: d
 
Explanation: Iron from its ore is converted to pig iron in a blast furnace. Ore iron is the purest form but it can not be used in this form.
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Saturday, February 8, 2020

FRACTURES SET 07
February 08, 2020

FRACTURES SET 07

FRACTURES SET 07

1. What is the deformation per unit length?

a) Strain
b) Stress
c) Toughness
d) Resilience

Answer: a

2. Ductility is indicated by _________
a) Percentage elongation
b) Percentage reduction
c) Poisson’s ratio
d) Elasticity

Answer: a

3. If a bar is doubled in length, what will be the strain induced?
a) 0.5
b) 1.0
c) 1.5
d) 2.0

Answer: b

4. Ductility is the opposite concept of _________
a) Toughness
b) Plasticity
c) Brittleness
d) Resilience

Answer: c

5. What term is used for the ratio of lateral strain to linear strain?
a) Bulk modulus
b) Elastic modulus
c) Shear strain
d) Poisson’s ratio

Answer: d

6. Material, if show identical properties in all directions, is said to be _________
a) Isotropic
b) Elastic
c) Ideal
d) Homogeneous

Answer: a

7. Which material has higher elasticity?
a) Rubber
b) Glass
c) Steel
d) Copper

Answer: c

8. _________ does not show linear stress strain relationship.
a) Rubber
b) Ceramic
c) Steel
d) Copper

Answer: a

9. The maximum stress up to which stress is proportional to strain is known as ________
a) Tensile stress
b) Compressive stress
c) Modulus of elasticity
d) Proportional limit

Answer: d

10. Yield strength represents resistance against _________
a) Fracture
b) Elastic deformation
c) Bending
d) Plastic deformation

Answer: d

11. Strain hardening causes more deformation on less stress application.
a) True
b) False

Answer: b

12. Necking causes drop in load after an ultimate tensile point.
a) True
b) False

Answer: a

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