some question related to viva and interview of Mechanical Engineering

1. Short Questions, Mechanical Engineering
101. Write down the Mechanical properties of metal
Ans: Mechanical properties are Brittleness, Ductility, hardness, Elasticity, Elongation, Toughness,
malleability, plasticity, strength, creep, fatigue,
102. What is Pyrometer? Mention its types
Ans: It’s a more scientific and reliable instrument for measuring temperatures of surface, it’s usually used
in measuring Furnace temperatures. It has two types
(A) Thermoelectric pyrometer (B) optical Pyrometer
103. Describe Reasons for heat treatments of Metal?
Ans: Reason for heat treatment are
 To soften the metal
 To hardened the metal
 To enable it to cut other metals
 To remove brittleness
 To refine structure
104. What are methods for heat Treatment?
Ans: Methods are
 Annealing
 Hardening
 Normalizing
 Quenching
 Tempering
105. What is hot working of Metal?
Ans: it consists of changing the shape of steel when its temperature is above critical temperature and is
used in hot rolling, forging, upsetting etc. Hot work refines the structure of steel by smashing up large
grain formation and closing any cavities which may be present.
106. How to measure % Elongation in Steel?
Ans: % Elongation is Measured by Formula
107. Mention the Process of Steel Manufacturing?
Ans: Processes for Steel Manufacturing are

2. Short Questions, Mechanical Engineering
 Open hearth Process
 Bessemer process
 The Crucible Process
 Electric steel
108. What is forging?
Ans: Forging is the manufacturing Process involving the Shaping of metal using localized Compressive
forces, the blows are delivered with a hammer or a die.
109. Enlist the hand tools for forging?
Ans: Hand tools are:
 Chisels
 Fullers
 Flatters
 Swages
 Punches and Drifts
 Tongs
110: write down any 4 Forging Operations?
Ans: Operations are
 Upsetting
 Drawing out
 Setting down
 Bending
111. Write down the Types of Chips and Define Built up edges?
Ans: Types are
1. Continuous chips
2. Discontinuous chips
3. Built up edge :
Built up Edge: this type of chip is very similar to continues chips with the difference that it has a built
up edge adjacent to tool face and also it is so smooth, obtained by machining Ductile materials.
112. Define Machinability?
Ans: Machinability is an index of the relative ease with which the chip can be separated from the base
material, the Higher the machinability the easier it is to machine the material.

3. Short Questions, Mechanical Engineering
113. Write down the Characteristics used to measure Machinability?
Ans: Characteristics are
 Cutting speed for a 60mint tool life
 Volume of material removed in this tool life
 Tool life in minutes
 Tool forces, energy or power required
 Temperature of metal
114. Define Malleability?
Ans: This is the property of permanently extending in all direction without rupture by passing,
hammering, rolling etc, it require that metal shall be plastic but is not so dependent on strength e.g Lead is
a very high malleable material.
115. What is the purpose of heat treatment?
Ans: Metal is heat treated to give certain desired properties according to requirements.
116. What is Case hardening?
Ans: Case hardening is a technique in which the metal surface is reinforced by adding of a fine layer at
the top of another metal alloy that is generally more desirable, Case hardening steel is normally used to
increase the object life.
117: Why tools are made of HSS?
Ans: Because it can stand with higher temperature without losing its temper hardness, this property
allows HSS to cut faster than high carbon steel.
118: Write down 2 basic types of Forging?
Ans: Types are
A. Hot or worm forging
B. Cold forging
119: Define forging operation punching and drifting?
Ans: When metal is at forging heat holes may easily be put in it by punching and opened out by driving
through a larger tapered punch called a drift.
120. Write down the advantages of cast iron?
Ans: Advantages are
 Cheapness
 Low melting point
 Easy to machine

4. Short Questions, Mechanical Engineering
121: Define Ductility?
Ans: A metal is ductile when it’s drawn out in tension without rupture
122. What does Elastic limit do?
Ans: Elastic Limit defines the elasticity of material.
123. What are applications of Carbon steel?
Ans: Wire rods, thin sheets, Axles, spring and Punches are made by CS
124. What is Lead and its gravity?
Ans: Lead is the heaviest of the common metal having a specific gravity of about 11.3
125: Define Tempering?
Ans: Tempering is a process of heat treating, which is used to increase the toughness of iron-
based alloys. Tempering is usually performed after hardening, to reduce some of the excess hardness, and
is done by heating the metal to some temperature below the critical point for a certain period of time, then
allowing it to cool in still air.
126: What are Tempering Temperatures?
Ans: Temperature Range is 230 to 600 degree centigrade.
127: What are the constituent of Pig Iron?
Ans: Carbon, silicon, sulpher, phosphorus, and Manganese are present in Pig iron obtained by blast
furnace.
128: From where cast iron is obtained?
Ans: Pig iron is processed in Cupola Furnace and Cast iron is obtained that we use for castings.
129: Define the properties ? 1.Plasticity 2.Toughness 3.strength
Ans:
Plasticty: a similar property to malleability and involving permanent deformation without rupture
Toughness: The amount of energy a material can absorb before its rupture
Strength: the strength of material is its ability to resist the application of force without rupture.

5. Short Questions, Mechanical Engineering
130: Define Quenching Process?
Ans: Quenching, a type of heat treating, is the rapid cooling of a work piece to obtain certain material
properties. It prevents low-temperature processes, such as phase transformations
131: What kinds of hammers are used in Hand forging?
Ans: the are two kinds of Hammers used in hand forging
 Hand hammers
 Sledge hammers
132: write down the Types of chisels?
Ans: Types are
 Hot chisels
 Cold chisels
 Bottom chisels
133: Enlist the types of joints in Welding?
Ans: types are
 Butt weld
 Scarf weld
 Vee and splice
 End prepared for
 Finish weld
134: Enlist the types of Riveting joints?
Ans: types are
 Double riveted lap joint
 Lap joint with single row of rivets
 Butt joints with single row cover plate
 Lap joint in a flat bar or strip
135: Define Cold Working?
Ans: Cold working means the subjecting of metals to force which cause it to undergo plastic deformation
when it is below the lower critical temperature.
136: Write down any 2 use of phosphor-bronze?
Ans: it is used for bearings which can carry heavy loads like worm wheels, gears.
137: Differentiate between Ferrous and nonferrous metals?

6. Short Questions, Mechanical Engineering
Ans: Ferrous metals are those metals which having iron and also having magnetic field e,g iron
While nonferrous metals are those which are having no iron and magnetic field.
138: What is hand Forging?
Ans: in that process the metal is heated up to red hot and then hammered to get required shape and size.
139: what is difference between Hot and cold Forging?
Ans: Hot forging and cold forging are two different metal forming processes that deliver similar results
During hot forging, the temperature reaches above the recrystallization point of the metal.
Cold forging deforms metal while it is below its recrystallization point. Cold forging is generally
preferred when the metal is already a soft metal, like aluminum.
140: Define Riveting and give some examples?
Ans: When plates have to be fastened together to form a permanent joint riveting process is done. That is
the only satisfactory method of making the joint and is extensively used in boiler works, shipbuilding and
structural constructions.
141: What are chisels?
Ans: these are tools used for cutting metals and for making prior to breaking.
142: Can you weld the wrought iron easily?
Ans: yes wrought iron can easily be welded and forged?
143: Write down the application of Iron?
Ans: iron is used in chains, cranes, hooks, railways and coupling instruments.
144: what are sledge hammers?
Ans: Sledge hammers are used by the striker not by the smith himself
145: in puddling furnace the heath in lined with which metals?
Ans: the furnace hearth is lined up with iron oxide and grey pig iron.
146: what is % of iron in wrought iron?
Ans: 99.9% iron
147: Where the Punches are used in Metal shop?
Ans: when metals are at forging heat holes may easily be put in it by punching.

7. Short Questions, Mechanical Engineering
148: Write down the Types of Milling Machines?
Ans: Types are
 Horizontal
 Vertical
 Universal
149: Name any 3 steel structure refining processes?
Ans: processes are
 Annealing
 Normalizing
 Tempering
150: What is brittleness?
Ans: Property of material to break up without permanent distortion.
151: Define Annealing?
Ans: to soften the Metal/ material is called annealing.
152: Name any 4 Metal Cutting operations?
Ans: Operation are
 Drilling
 Turning
 Shaping
 Milling
153: Define machinability?
Ans: The Machining with respect to time is called machinability
154: What could be max. height of anvil?
Ans: Max. height of anvil could be 600mm
155: Name 3 variables that effect chip formation?
Ans: Variables are
1. Properties of work material
2. Properties of tool material
3. Tool geometry

8. Short Questions, Mechanical Engineering
156: Write down the Taylor tool life equation with its details?
Ans: Taylor Tool-life Equation is
VTn
=C where
V=Cutting speed (ft/min or m/sec)
T=tool life
n= Taylor tool life exponent
C= Taylor tool life constant (ft/min or m/sec)
157. Write down the types of machining?
Ans: Types are
A. Single point cutting (turning, planning, shaping and boring)
B. Multipoint cutting (drilling, milling, grinding, polishing, broaching, reaming)
158: Write down the types of milling?
Ans: there are two types
1. Conventional milling (up)
2. Climb millimg (down)
159: What is Up milling?
Ans: In up milling the chip formed starts thin and then increases as the cutter advances into
work.
160: what is Down milling?
Ans: In that type the chip formed starts thick and decreases as the cutter advances to the finished
surface
161: Write the difference between machining and other two primary forming processes?
Ans: In machining process material is removed from a general bulk shape to obtain the desired
three dimension shape.
162: How many types of drives of shaper? Also mention the names?
Ans: There are two types mechanical and hydraulic.

9. Short Questions, Mechanical Engineering
163: Write the names of ores that are representing the carbonates?
Ans: Spathic ores, Clay band ores and Black band ores.
164: What is the effect of Sulphur and manganese on cast iron?
Ans: These two elements has the same general effect, a tendency to harden the iron. Too much
sulphur promotes unsound casting.
165: Write the name of process by which surface of low carbon steel can make hard?
Ans: Case hardening
166: From which type of steel cold chisel, press dies, punches are made?
Ans: Cold chisel, press dies and punches are made from high carbon steel.
167: What is the relative density of steel?
Ans: Relative density of steel is 7.8.
168: For which reason aluminum alloy is used for engine piston?
Ans: Aluminum alloy has characteristics of retaining good strength at high temperature.
169: Write down the name of two large industrial users of lead?
Ans: There are two large industrial users, Electrical industries and Paint industries.
170: What is the material of swage block?
Ans: Swage block is made of cast iron.
171: Write down the Primary tool wear failure mechanism?
Ans:
1) Flank wear
Rough cut 0.03 in
Finish cut 0.015 in
2) Crater wear
172: Write the types of cutting when horizontal milling is used?
Ans: 1) Conventional milling 2) Climb milling

10. Short Questions, Mechanical Engineering
173: Write down the name of chief ores of iron?
Ans: Oxides and carbonates.
174: What is thermocouple?
Ans: A thermoelectric device for measuring temperature, consisting of two wires of different
metals connected at two points.
175: What is composition of acicular iron and for which purpose it is used?
Ans: Acicular iron has nickel and molybdenum in its composition and is being used for cast
crankshafts.
176: Write the name of type of steel by which wire rod, thin sheets, and solid drawn tubes?
Ans: Dead mild steel
177: What is relative density of aluminum?
Ans: Relative density of aluminum is 2.68
178: What is shape of fracture of cast iron?
Ans: It is granular but when forged or rolled it is slightly fibrous.
179: Which material is used for machining the non-ductile materials such as cast iron, brass?
Ans: Tungsten carbide
180: What is coke breeze?
Ans: Coke breeze is gas coke crushed into small pieces about 10 to 12mm
181: What is the purpose of normalizing?
Ans: The basic purpose is to refine structure of steel and the remove strains which is cause by
cold working
182: Define etching process?
Ans: It is process use when require to see micro structure of metal in which polish metal is dip in
H2So4, Hcl which etches the constitute & their boundaries.
183: What is the machining?
Ans: Machining is term that is used for material removing with the help of tool.

11. Short Questions, Mechanical Engineering
184: Enlist angle of single point cutting tool?
Ans: Angles are
 Side rake angle
 Back rake angle
 Side cutting edge angle
 End cutting edge angle
 Side relief angle
 End relief angle
185: Define broaching process?
Ans: It is a process in which we make grooves on the surface so that it installs on exact place for
example groove of front sprocket of bike.
186: what is the purpose of fullers?
Ans: Use for the necking down a place of work. The reduction often serving the starting point
for a reduction.
187: Define drawing down process?
Ans: It is the process of increasing length of bar at expense of thickness or width.
188: How many factor which tend to cause the metal to warp & crack?
Ans: They are two factors which tend to cause the metal to warp and crack.
 When metal is cooled undergoes general contraction which is not uniform but
occurs first at the outside surface and in the thin section of articles.
 When steel cools through the critical range and expansion take place.

12. Short Questions, Mechanical Engineering
189: What are purposes of annealing?
Ans: purposes are
 To soften the steel so that it may be more easily machined.
 To relieve internal stresses which may have been caused by working the metal.
190: Why to forge instead of weld wrought iron?
Ans: Because it is ductile and bends easily when cold, in fact a medium sized bar with stand
being doubled.
191: what are tongs? Mention its chief types?
Ans: Tong is the hold his work during the various operations. The chief types of tongs for
holding work are following
 Flat tongs
 Tongs for round work
 Pick up tongs
192: What is the casting process?
Ans: A casting is produced by pouring molten metal into a mould made to the shape of part
required.
193: What is bending?
Ans: Bending is an important operation in forging and one very frequently used. Bends may be
either sharp cornered angle bends.
194: What is rack angle of cutting tool?
Ans: The cutting tool’s rack angle is the angle between the cutting edge and the cut itself. It may
be positive, negative or neutral.

13. Short Questions, Mechanical Engineering
195: Define turning operation?
Ans: Turning is the metal cutting operation to reduce the diameter of work piece.
196: what are Flatters?
Ans: Flatters are used for finishing flat surface and are made with a perfectly flat surface. The set
hammer is a similar but smaller tools used for finishing corners & confined spaces.
197: Write down the types of milling machine?
Ans: Types of milling machine following are
 Vertical
 Horizontal
 Universal
 Bed type
 Knee & column type
198: Define types of steel?
Ans: Steel may be roughly classified as straight carbon steel and alloy steel. Straight carbon steel
is one that owes its particular properties chiefly to the presence of certain percentages of carbon
without substantial amount of other alloying elements.
199: What is important element in straight carbon steel?
Ans: Carbon is the element that makes possible the hardening of straight carbon steel.
200: How much carbon should be present in steel before it can be hardened noticeably?
Ans: Steel must contain at least 0.20 percent of carbon before it can be hardened sufficiently for
commercial use.

14. Short Questions, Mechanical Engineering
201: What is low carbon steel?
Ans: A low carbon steel is one that does not contain enough carbon to cause it to hardened when
heated to a high temperature and quenched in oil, water or brine. The amount of carbon in low
carbon steel may vary from 0.05 to 0.20 percent.
202: What is a medium carbon steel?
Ans: Medium carbon steel is one that contains 0.20 to 0.60 percent carbon.
203: What is high carbon steel?
Ans: High carbon steels are those which contain about 0.60 to 1.30 percent of carbon.
204: What are alloy steel?
Ans: Alloy steels are those that contain in addition to carbon and iron alloying element such as
chromium, vanadium, nickel, molybdenum or manganese.
205: What is the principle reason for heat treatment?
Ans: there are two reasons mainly
 Harden
 Soften
206: How the hardness of steel could be judged?
Ans: The color of cooling steel represents the temperature and degree of hardness.
207: What methods are used to temper steel?
Ans: The method to use the temper steel will depend upon the kind of steel being used its size its
shape and what is to be used for.
208: Can more than one tool tempered?
Ans: Modern production requires that machine parts and tools be hardened in batches. When
more than one tool is being tempered it is more practical to re heat the parts or tools in a
bath of oil or nitrate in a pyrometer controlled heating pot.
209: What is steel?
Ans: Steel is an alloy of iron and carbon. In addition there are minute percentages of other
element present.

15. Short Questions, Mechanical Engineering
210: Why we prefer cast iron in castings?
Ans: because
 It can be used for large size of casting products.
 It can melt easily.
211: What is the temperature of blast furnace?
Ans: 2600F TO 3600F
212: Why we make alloy?
Ans: To increase the property of material as hardness, toughness, strength or ductility of
material.
213: What are uses cupola furnace?
Ans: uses are
 For prepare the steel
 Change the property of steel.
FILE IS COMPOSED BY
Muddassarlatifawan@gmail.com
University of Lahore