Multiple choice question for engineering
Set 1
1. If we decrease the freezing range then the fluidity of metal will?
a) Increase
b) Decrease
c) Will not change
d) Will increase then decrease
Answer
Answer: a [Reason:] Fluidity is inversely proportional to freezing range. When freezing range decreases, fluidity of metal will increase.
2. According to Chvorinov’s rule the solidification time is a function of volume and surface area and is given by the relationship between volume, area and some exponential power ‘n’. Here the value of n is
a) 1
b) 2
c) 3
d) 4
Answer
Answer: b [Reason:] n=2 in Chvorinov’s rule. Solidification time is a function of volume and surface area as stated by Chvorinov’s rule.
3. Which one of the following expands during contraction?
a) Mild steel
b) Grey cast iron
c) Aluminium
d) Copper
Answer
Answer: b [Reason:] Grey cast iron expands upon contraction. Mild steel, Aluminium and copper do not expands during contraction process.
4. Dissolved gases may be removed from molten metal by
a) Flushing or purging with inert gas
b) Melting and pouring the metal in vacuum
c) Both of the mentioned
d) None of the Mentioned
Answer
Answer: c [Reason:] Dissolved gases may be removed from molten metal either by flushing or purging with inert gas or melting and pouring the metal in vacuum.
5. Doubling the time in flat mould will increase the thickness of wall skin by what percentage?
a) 31.6%
b) 41%
c) 73%
d) 22%
Answer
Answer: b [Reason:] Thickness is proportional to √ time. When time is doubled in flat mould, thickness of wall skin will increase by 41%.
6. Solidification of casting does not depend upon which factor?
a) Type of metal
b) Thermal properties of metal
c) Geometric relationship between volume and surface area
d) Surface tension.
Answer
Answer: d [Reason:] Surface tension is a fluid property and solidification time of casting does not depend upon any fluid property.
7. The following characteristic of molten metal influence the fluidity
1) Mushy zone
2) Viscosity
3) Surface tension
4) Inclusion
Which one of the following is correct?
a) 1,2
b) 1 only
c) 1,2,3
d) 1,2,3,4
Answer
Answer: d [Reason:] All the above mention characteristics influence fluidity. Fluidity in casting is used to designate the casting material ability to fill the mould cavity.
8. What is the function of cores used in casting?
a) To remove dissolved gases
b) To avoid defects
c) To form hollow region
d) To reduce shrinkage porosity
Answer
Answer: c [Reason:] Cores are used to form hollow region. It is difficult to form hollow region in a material using sand casting.
9. Which one of the statement is correct in metal casting?
a) Rapid cooling produces a solidified skin or shell
b) Those grain that have favorable orientation will grow preferentially
c) Cast iron has wide mushy zones
d) Lack of uniformity in grains size and distribution will cause anisotropic properties
Answer
Answer: c [Reason:] Cast iron has low range of mushy zone.Rapid cooling produces a solidified skin or shell and Lack of uniformity in grains size and distribution will cause anisotropic properties.
10. Assertion (A): Chills are used to reduce shrinkage porosity.
Reason (R): the function of chill is to increase the rate of solidification in critical region.
a) Both A and R is correct and R is a correct explanation for A
b) Both A and R is correct and R is an incorrect explanation for A
c) A is wrong but R is correct
d) A is correct but R is wrong
Answer
Answer: a [Reason:] Chills are used to reduce shrinkage porosity and the function of chill is to increase the rate of solidification in critical region.
Set 2
1. Consider a situation in which a welding operation is being performed with V = 20 volts, I = 200 A, and the cross-sectional area of the weld bead is 30 mm2. Estimate the welding speed if the workpiece and electrode are made of (a) aluminum, (b) carbon steel, and (c) titanium. Use an efficiency of 75%.
a) 35 mm/s
b) 34.5 mm/s
c) 36 mm/s
d) 46 mm/s
Answer
Answer: b [Reason:] For aluminum, the specific energy required is u = 2.9 J/mm3
Therefore,
v = e(VI/uA)
= (0.75) [(20/200)/(2.9/30)]
= 34.5 mm/s
2. Upon which of the following parameters does the current intensity in arc welding depend?
a) stability of arc
b) electrode diameter
c) gap between the electrode and parent metals
d) thickness of parent metals
Answer
Answer: b [Reason:] Electrodes for consumable arc-welding processes are classified according to the following properties:
a) Strength of the deposited weld metal
b) Current (Ac or Dc)
c) Type of coating.
3. In ___________________ welding two non consumable electrodes are used.
a) MIG
b) TIG
c) atomic hydrogen
d) submerged arc
Answer
Answer: c [Reason:] In MIG welding consumable electrodes are used. In TIG only one non consumable electrode is used. And in atomic hydrogen welding only two non consumable electrodes are used.
4. ______________ brazing process is good for mass scale.
a) Furnace
b) Induction
c) Dip
d) Torch
Answer
Answer: a [Reason:] As in furnace brazing at once mass materials could be brazed.
5. For grey cast iron, which of the following welding methods is preferable?
a) MIG
b) submerged arc
c) gas flame
d) electric arc
Answer
Answer: a [Reason:] As the percentage of carbon in grey cast iron is less, therefore MIG welding is more preferable.
6. Due to which of the following reasons, no flux is used in atomic hydrogen welding?
a) The burning hydrogen shields the molten metal
b) Two electrodes are coated which gradually release the flux
c) The filler rod is coated with flux
d) One of the two electrodes is coated which releases the flux
Answer
Answer: a
7. In resistance welding, between the electrodes, a current of __________ voltage and __________ ampere is passed.
a) high, high
b) high, low
c) low, low
d) low, high
Answer
Answer: d [Reason:] As this processes have major advantages, such as not requiring consumable electrodes, shielding gases, or flux.
8. _____________ is the welding process in which heat is produced for welding by chemical reaction.
a) Resisting welding
b) Thermit welding
c) Forge welding
d) Gas welding
Answer
Answer: b [Reason:] In forge welding metal is heated in an open hearth. In gas welding heat is produced by pressurizing the gas and in resistance welding heat is produced by electrodes and current. But only in thermit welding heat is produced by chemical reactions.
9. In case of submerged arc welding, the electrodes upto __________diameter may be used.
a) 30 mm
b) 20 mm
c) 15 mm
d) 12 mm
Answer
Answer: d
10. In arc welding, arc in created between the electrode and work by
a) contact resistance
b) flow of voltage
c) flow of current
d) electrical energy
Answer
Answer: d
11. Material used for coating the electrode is called
a) flux
b) slag
c) protective layer
d) deoxidiser
Answer
Answer: a [Reason:] Slag is the deposited electrode after welding. Flux is the coating of various materials on electrode.
12. ___________ is the welding process in which two pieces to be joined are overlapped and placed between two pointed electrodes.
a) Seam welding
b) Resistance welding
c) Projection welding
d) Spot welding
Answer
Answer: d [Reason:] Spot welding is the simplest and most commonly used resistance~welding process. Welding may be performed by means of single (most common) or multiple pairs of electrodes (as many as a hundred or more), and the required pressure is supplied through mechanical or pneumatic means.
13. Which of the following gases are used in Tungsten inert gas welding?
a) Helium and neon
b) Hydrogen and oxygen
c) Argon and helium
d) Carbon dioxide and hydrogen
Answer
Answer: c
14. Preheating is essential in welding
a) copper
b) aluminium
c) cast iron
d) stainless steel
Answer
Answer: c [Reason:] As the weldability of cast iron usually decreases as the amount of free carbon in cast iron increases, so it is preheated to a dull red and then welded.
15. The temperature, in arc welding, is of the order of
a) 20000
b) 30000
c) 55000
d) 70000
Answer
Answer: c
Set 3
1. Gas welding is also known as?
a) Oxy fuel gas welding
b) Metallic welding
c) Arc welding
d) Fuel gas welding
Answer
Answer: a [Reason:] Gas welding is also known as oxy fuel gas welding. In gas welding fuel gases are used to generate high amount of heat and melt the metal.
2. How many types of flames are there?
a) 1
b) 2
c) 3
d) 4
Answer
Answer: c [Reason:] There are 3 types of flame. (Neutral flame, oxidizing flame and carburizing flame). In neutral flame oxygen is in same proportion with acetylene.
3. In which flame oxygen is in same proportion?
a) Neutral flame
b) Oxidizing flame
c) Carburizing flame
d) None of the mentioned
Answer
Answer: a [Reason:] In neutral flame oxygen is in same proportion with acetylene. Oxidizing flame is used for welding of brass, bronze and copper-zinc.
4. In which flame oxygen is in excess?
a) Neutral flame
b) Oxidizing flame
c) Carburizing flame
d) None of the mentioned
Answer
Answer: b [Reason:] In oxidizing flame oxygen is in excess. In neutral flame oxygen is in same proportion with acetylene. Oxidizing flame is used for welding of brass, bronze and copper-zinc.
5. In which flame the ratio of oxygen is deficient?
a) Neutral flame
b) Oxidizing flame
c) Carburizing flame
d) None of the mentioned
Answer
Answer: c [Reason:] In carburizing flame the ratio of oxygen is deficient. Reducing flame is used for the welding of low carbon and alloy steel monel metal.
6. Which of the following flame is harmful for steel?
a) Neutral flame
b) Oxidizing flame
c) Carburizing flame
d) All of the mentioned
Answer
Answer: b [Reason:] Oxidizing flame oxidizes the steel. In oxidizing flame oxygen is in excess. In neutral flame oxygen is in same proportion with acetylene. Oxidizing flame is used for welding of brass, bronze and copper-zinc.
7. For brazing, soldering and flame hardening which of the following flame is used?
a) Neutral flame
b) Oxidizing flame
c) Carburizing flame
d) All of the mentioned
Answer
Answer: c [Reason:] For brazing, soldering and flame hardening carburizing flame is used. Reducing flame is used for the welding of low carbon and alloy steel monel metal.
8. The inner cone of the flame has______ temperature?
a) Highest
b) Coldest
c) Moderate
d) Can’t say
Answer
Answer: a [Reason:] The inner cone of the flame has the highest temperature. The outer cone of flame has lowest temperature. The inner cone of the flame has 3500 degree centigrade.
9. The oxy acetylene gas welding is a type of?
a) Endothermic reaction
b) Exothermic reaction
c) Neutral reaction
d) All of the mentioned
Answer
Answer: b [Reason:] The oxy acetylene gas welding is a type of exothermic reaction. 1 mole of acetylene can produce KJ/mol of heat.
10. The chemical formula of acetylene is?
a) C2H4
b) C2H6
c) C2H5OH
d) C2H2
Answer
Answer: d [Reason:] The chemical formula of acetylene is C2H2. 1 mole of acetylene can produce KJ/mol of heat. Gas welding is also known as oxy fuel gas welding.
Set 4
1. In which type of gating system aspiration effect takes place?
a) Vertical
b) Horizontal
c) Diagonal
d) Bottom
Answer
Answer: a [Reason:] Aspiration effect takes place in vertical gating system. Aspiration is formation of bubble during the molding process.
2. The gating ratio Sprue area: Runner area: In gate area for non pressurized casting is?
a) 1:2:2
b) 2:2:1
c) 1:4:4
d) 1:4:2
Answer
Answer: c [Reason:] The gating ratio Sprue area: Runner area: In gate area for non pressurized casting is 1:4:4. Sprue area is smallest.
3. Which of the following is a type of riser?
a) Top
b) Blind
c) Internal
d) All of the Mentioned
Answer
Answer: d [Reason:] All the above mentioned is a type of riser. Riser can be top at the top portion of design. It can be blind, on the both side or it can be internal.
4. Caine curve is a graph between?
a) Volume ratio and Solidification ratio
b) Volume ratio to freezing ratio
c) Volume ratio to heating ratio
d) Freezing ratio to time ratio
Answer
Answer: b [Reason:] Caine curve is a graph between volume ratios to freezing ratio. Caine curve is used to determine exact volume for perfect freezing.
5. To prevent heavier and lighter impurities which of the following system is used?
a) Skim bob
b) Pouring basin
c) Strainer
d) Splash core
Answer
Answer: a [Reason:] To prevent heavier and lighter impurities skim bob is used. Skin bob does not allow to impurities to reach mould cavity.
6. To reduce the eroding force of the liquid metal which of the following system is used?
a) Skim bob
b) Pouring basin
c) Strainer
d) Riser
Answer
Answer: b [Reason:] To reduce the eroding force of the liquid metal pouring basin is used.
7. If velocity of metal flow at gate is 4m/sec, volume of mould is .1 cubic meters and the cross sectional area of gate is 0.002 cubic meters then the time required to fill up the mould in seconds is?
a) 10
b) 12
c) 12.5
d) 15.5
Answer
Answer: c [Reason:] t = [v/ (a*V)], where v is volume, V is the velocity, a is the area and t is the time taken to fill the mould.
8. If the volume is to area ratio for riser is 2 and for casting it is 4 then the freezing ratio is?
a) 2
b) 4
c) 8
d) .5
Answer
Answer: d [Reason:] F.R = (volume is to area ratio of riser/ volume is to area ratio of casting). It used to get relative value of mould freezing time.
9. Time required to fill the mould by vertical gating system is ______ to bottom gating system?
a) Less
b) More
c) Equal
d) None of the Mentioned
Answer
Answer: a [Reason:] Time required to fill the mould by vertical gating system is less than bottom gating system.
10. A mould has a down sprue length of .2 meters. The velocity of metal in meter/second at gate will be?
a) 1.78
b) 1.98
c) 2.3
d) 2.5
Answer
Answer: b [Reason:] Velocity = √(2*g*h), where h is the length of down sprue, and g is the value of earth gravity which can be taken as 9.81.
Set 5
1. Part of twist drill which carries flutes and extends from dead centre up to the start of neck is known as
a) Body
b) Point
c) Lip
d) Chisel edge
Answer
Answer: a [Reason:] Body of twist drill carries flutes and extends from dead centre up to the start of neck. This is the longest part of twist drill.
2. Part of drill between neck and tang is known as
a) Body
b) Point
c) Shank
d) Chisel edge
Answer
Answer: c [Reason:] Shank of twist drill is between neck and tang.
3. Edge formed at extreme tip due to intersection of flanks, is known as
a) Body
b) Point
c) Lip
d) Chisel edge
Answer
Answer: d [Reason:] Chisel edge is formed at extreme tip due to intersection of flanks. It is at the extreme edge of chisel edge.
4. Cone shaped surface formed at the end of the flutes which contains dead centre, lips and flanks etc. is known as
a) Body
b) Point
c) Lip
d) Chisel edge
Answer
Answer: b [Reason:] Point is a Cone shaped surface formed at the end of the flutes which contains dead centre, lips and flanks etc. It is at the end part of the twist drill.
5. Main cutting part of drill is
a) Body
b) Point
c) Lip
d) Chisel edge
Answer
Answer: c [Reason:] Lip is the main cutting part of drill and is also called cutting edge. Material removed first at chisel edge.
6. Intersection of each faces and flank form
a) Body
b) Point
c) Lip
d) Chisel edge
Answer
Answer: a [Reason:] Lip is the main cutting part of drill and is also called cutting edge. It is formed at Intersection of each faces and flank.
7. Small clearance provided in diameter of twist drills adjacent to land is known as
a) Body clearance
b) Point clearance
c) Lip clearance
d) Chisel edge clearance
Answer
Answer: a [Reason:] Body clearance is provided in diameter of twist drills adjacent to land. This clearance help in the removal of material during cutting.
8. Which of the following help in reducing friction between drill and the walls of the hole in twist drills?
a) Body clearance
b) Point clearance
c) Lip clearance
d) Chisel edge clearance
Answer
Answer: a [Reason:] Body clearance reduces friction between drill and the walls. It helps in smooth drilling of holes during the operation.
9. Narrow flat surface running along flutes of twist drill on its leading edge is known as
a) Body
b) Point
c) Lip
d) Land
Answer
Answer: d [Reason:] Land is the narrow flat surface running along flutes of twist drill on its leading. It is the flat part of twist drill.
10. Narrow flat surface running along flutes of twist drill on its leading edge is known as
a) Body
b) Point
c) Lip
d) Margin
Answer
Answer: d [Reason:] Margin is the narrow flat surface running along flutes of twist drill on its leading. It is also known as land.