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# UPPSC Polytechnic Lecturer Exam Preparation Mechanical Engineering Most Expected Questions

UPPSC Polytechnic Lecturer Exam Preparation Mechanical Engineering Most Expected Questions. The UPPSC Polytechnic Lecturer Exam is to be conducted on 22nd December 2021. UPPSC Polytechnic Lecturer Exam 2021 is conducted to recruit lecturers for Government polytechnic Colleges in UP for Technical Subjects. Hence the majority of questions in the exam are from respective technical domains but there are a few questions from GENERAL HINDI and GENERAL KNOWLEDGE part also to check one’s general communication skills understanding of the society. Generally, Aspirants don’t find any difficulty in the preparation of the technical part of the examination. So, for the help of aspirants, we are providing the Most Expected Questions with solutions of Mechanical Engineering for UPPSC Polytechnic Lecturer Recruitment 2021. This is exclusively provided by ADDA247 to all the UPPSC Polytechnic Lecturer Recruitment 2021 for FREE!!

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## UPPSC Polytechnic Lecturer Mechanical Engineering Most Expected Questions

Q1. The state of stress at a point in a loaded member is = 400 MPa, = –400 MPa and = 300
MPa. The principal stresses and are
(a) 300 MPa and –700 MPa
(b) 400 MPa and –600 MPa
(c) 500 MPa and – 500 MPa
(d) 600 MPa and – 400 MPa

Q2. While selecting the elements of power transmission with speed reduction, the order of
preference based on a minimum cost is
(a) spur gear, belt pulley, worm and worm wheel
(b) belt pulley, spur gear, worm and worm and worm wheel
(c) worm and worm wheel, spur gear, belt pulley
(d) worm and worm wheel, belt pulley, spur gear

Q3. Consider the following statements:
1. State of plane stress occurs at the surface
2. State of plane strain occurs at the surface
3. State of plane stress occurs in the interior part of the plate
4. State of plane strain occurs in the interior part of the plate
Which of these statements are correct?
(a) 1 and 3
(b) 2 and 4
(c) 1 and 4
(d) 2 and 3

Q4. A 16 mm diameter bar elongates by 0.04% under a tensile force of 16 kN. The average
decrease in diameter is found to be 0.01%. Then
1. E = 210 GPa and G = 77 GPA
2. E = 199 GPa and v = 0.25
3. E = 199 GPa and v = 0.30
4. E = 199 GPa and G = 80 GPa
Which of these values are correct?
(a) 3 and 4
(b) 2 and 4
(c) 1 and 3
(d) 1 and 4

Q5. Two strain gauges fixed along the principal directions on a plane surface of a steel
member recorded strain values of 0.0013 tensile and 0.0013 compressive respectively.
Given that the value of E = 2 × MPa and =0.3, the largest normal and shearing stress at this
point are
(a) 200 MPa and 200 MPa
(b) 400 MPa and 200 MPa
(c) 260 MPa and 260 MPa
(d) 260 MPa and 520 MPa

Q6. A beam is said to be of uniform strength if
(a) The bending moment is the same throughout the beam
(b) The shear stress is the same throughout the beam
(c) The deflection is the same throughout the beam
(d) The bending stress is the same at every section along its longitudinal axis

Q7. The diameter of a solid shaft made of mild steel, rotating at 250 r.p.m. is 45 mm. The
shaft is designed to transmit 50 kW. What will be the factor of safety if the ultimate shear
stress at yield is 427 N/mm²?
(a) 6
(b) 5
(c) 4
(d) 3

Q8. Newton’s Law of viscosity states that “Shear stress” is directly proportional to
(a) Velocity
(c) Shear strain
(d) Viscosity

Q9. If σ be the surface tension of the water, ρ be the mass density g be the gravitational
accelerations and d be the diameter of the glass tube, then the capillary rise of water in the
glass tube h will be
(a)
(b)
(c)
(d)

Q10. The pressure difference (in Pa) in a droplet of a fluid of 0.002m diameter with surface
tension of 0.01 N/m is
(a) 10
(b) 20
(c) 4 π
(d) 0.0004 π

Q11. A force of 400 N is required to open a process control valve. What is the area of
diaphragm needed for a diaphragm actuator to open the valve with a control gauge
pressure of 70 kPa?
(a) 0.0095
(b) 0.0086
(c) 0.0057
(d) 0.0048

Q12. An oil which has kinematic viscosity 0.2 stokes flows through a circular pipe of 1cm
radius. The velocity at which the flow will be critical is about
(a) 2.0 m/s
(b) 1.5 m/s
(c) 0.5 m/s
(d) 4.0 m/s

Q13. ‘A fluid is at rest’ it means that
(a) The fluid has zero normal stress and non-zero shear stress.
(b) The fluid has non-zero normal stress and zero shear stress.
(c) The fluid has non-zero normal stress and shear stress.

(d) The fluid has zero-normal stress and zero shear stress.

Q14. The flammable fuels have the flash point at the temperature of
(a) More than the 37.8ºC
(b) Less than 37.8ºC
(c) No temperature limits
(d) Only pressure dependency
Q15. In a 4–cylinder, 4–stroke Diesel engine operating at 1200 rpm, the duration of fuel
injection is . The time in seconds during which fuel is injected would be
(a)
(b)
(c)
(d)

Q16. In S.I. engine, the throttle valve of carburetor controls the quantity of
(a) Fuel
(b) Air
(c) Fuel and air mixture
(d) Lubricating oil
Q17. Which of the following number decide the ignition quality of diesel fuel?
(a) Octane number
(b) Cetane number
(c) Carbon percentage
(d) Calorific value

Q18. 1 kg of carbon produces following weight of in flue gases
(a) 44 kg
(b) 22 kg
(c) 11 kg

(d) 11/3 kg

Q19. The volume of charge that can be available in an engine after suction, if the clearance
volume is 20 cc and swept volume is 400 cc. Consider mechanical efficiency and volumetric
efficiency of engine as 90% and 80% respectively.
(a) 288 cc
(b) 270 cc
(c) 256 cc
(d) 320 cc
Q20. The elastic constants, E, G and K are related by the expression:
(a)
(b)
(c)
(d)
Q21. Which material has the highest value of Poisson’s ratio?
(a) Rubber
(b) Copper
(c) Steel
(d) Concrete
Q22. In a tensile test of a specimen, the ratio of maximum load to the original cross-
sectional area of the test piece is called:
(a) Ultimate stress
(b) Sea stress
(c) Breaking stress
(d) Yield stress
Q23. A steel bar is fixed at both ends. If the bar is heated, it will develop-
(a) Compressive stress

(b) tensile stress
(c) Bending stress
(d) None of the above
Q24. The value of poison’s ratio is always less than –
(a) 1
(b) 0.2
(c) 0.4
(d) 0.5

Q25. Stress due to change in temperature developed in a bar depends upon:
(a) coefficient of thermal expansion
(b) thermal conductivity
(c) density
(d) Poisson’s ratio
Q26. Corrosion resistance of steel is increased by adding
(a) Carbon
(b) Manganese
(c) Magnesium
(d) Chromium
Q27. Which of the following is the solid solution of carbon in gamma iron?
(a) Martensite
(b) Ferrite
(c) Austenite
(d) Cementite

Q28. If steel is cooled in still air, the structure obtained is

(a) Pearlite
(b) Sorbite

(c) Troosite
(d) Martensite

Q29. A satellite is kept on moving in its orbits around the earth due to ……………
(a) Centrifugal force
(b) Centripetal force
(c) Gravitational force
(d) Resultant force acting on satellite
Q30. What term is used for the combined effect of all the forces on a body
(b) Stress
(c) Strain
(d) None of these
Q31. The use of the D Alembert’s principle is for……….
(a) Determining the stresses in the truss
(b) Stabilities of floating bodies
(c) Reduction of problems of kinetics to equivalent static problem
(d) Design of safe structures
Q32. Effort lost in friction in a simple machine is-
(a)
(b)
(c)
(d)

Q33. Which of the following term can also be used to state the dynamic equilibrium?
(a) Translatory equilibrium
(b) Static equilibrium
(c) Kinetic equilibrium

(d) Rotational equilibrium
Q34. The function of washer is to______________.
(a) provide cushioning effect
(b) provide bearing area
(c) absorb shocks and vibrations
(d) provide smooth surface in place of rough surface

Q35. In compression test, the cast iron specimen would fracture along:
(a) an oblique plane
(b) at right angles to the axis of specimen
(d) would not occur

Q36. A cotter joint is used to transmit:
(c) Combined axial and twisting load
(d) Axial tensile and compressive loads
Q37. Rankine cycle consist of:
(a) Two isobaric &amp; two isothermal processes
(b) Two isothermal &amp; two isochoric processes
(c) Two isobaric &amp;two isentropic processes
(d) Tow isothermal &amp; two isentropic processes
Q38. In a Rankine cycle, the work output from a turbine is a change;
(a) in internal energy between the inlet and outlet
(b) in volume between the inlet and outlet
(c) in entropy between the inlet and outlet
(d) of enthalpy between the inlet and outlet

Q39. Cochran boiler is a:
(a) Horizontal fire-tube boiler
(b) Horizontal water – tube boiler
(c) Vertical water – tube boiler
(d) Vertical fire – tube boiler
Q40. The steam in boiler drum is always
(a) saturated
(b) dry
(c) superheated
(d) wet or dry
Q41. In a water – tube boiler, the flue gas flows through the following accessories:
1. Superheater
2. ID Fan
3. Air heater
4. Economizer
Which of the following gives the correct sequence of the flue gas through these accessories?
(a) 1, 2, 3, 4
(b) 3, 1, 4, 2
(c) 1, 4, 3, 2
(d) 1, 3, 2, 4
Q42. In a boiler, the feed check valve is used to-
(a) control the feed water flow rate
(b) check the water level in drum
(c) ensure unidirectional feed flow to drum
(d) check quality of feed water

Q43. Boiler accessories are used to ensure:

(a) improved performance
(b) safe operation
(c) automatic control
(d) easy maintenance
Q44. Dynamic viscosity of Pseudo plastic fluid is
(a) decrease as the rate of shear increases
(b) Increases as shear increases
(c) Increase as the rate of shear increases
(d) Increases with the time for which shearing forces are applied

Q45. The pressure inside a soap bubble of 100 mm diameter is 50 N/m² above the
atmospheric pressure. The surface tension in soap film would be
(a) 0.625 N/m
(b) 0.312 N/m
(c) 0.162 N/m
(d) 0.078 N/m
Q46. The centre of buoyancy is defined as the
(a) Centre of gravity of the body
(b) Point of intersection of the buoyant force and the gravitational force
(c) Point of intersection of the buoyant force and the centre line of the body
(d) Centre of the volume of the displaced fluid
Q47. The fluid element of a fluid in an irrotational motion
(a) do not undergo any shear
(b) do not undergo a circular motion
(c) has the circulation around any path is zero
(d) has the viscosity may not be zero
Q48. The robot which is most accurate is

(a) Cartesian robot
(b) Polar robot
(c) Spherical robot
(d) Articulated
Q49. In JIT production, the ideal batch size consists of
(a) one part
(b) two parts
(c) ten parts
(d) five parts

Q50. The indication of positive slack in PERT is
(b) Beyond of schedule
(c) As per schedule
(d) Critical path

Q51. The North West Corner rule in LPP
(a) is used to find an initial feasible solution
(b) is used to find an optimal solution
(c) is based on the concept of minimizing opportunity cost
(d) none of the above
Q52. In sampling, AQL is
(a) Average quality level
(b) Acceptable quality level
(c) Asymmetric quality level
(d) Available quality level
Q53. Acceptance sampling is used in
(a) Job Production

(b) Batch Production
(c) Mass Production
(d) All of these
Q54. The number of fundamental motions involved in micro-motion study is
(a) 12
(b) 8
(c) 20
(d) 16
Q55. The Symbol which is used for operation in work study is
(a) 
(b) ⇒
(c) T
(d) O
Q56. The motor which will be suitable for traction?
(a) DC series motor
(b) DC shunt constant speed
(d) compound motor
Q57. The abrasive which is natural?
(a) Garnet
(b) Emery
(c) Diamond
(d) All of the these
Q58. In a turning tool, crater wear occurs on _____.
(a) Base
(b) Flank face

(c) Rake face
(d) Shank
Q59. In an ideal vapor compression refrigeration cycle, the specific enthalpy of refrigerant
at the following state is given as (kJ/kg)
Inlet of condenser: 283
Exit of condenser: 116
Exit of evaporator: 232
The COP of this cycle is
(a) 2.27
(b) 2.75
(c) 3.27
(d) 3.75
Q60. A high thermal diffusivity represents
(a) High storage, less conduction of heat
(b) Less storage, more conduction of heat
(c) There is always equal amount of conduction and storage since it is a property
(d) It has no relevance
Q61. If V=volume, A = surface area, h = surface film conductance, = density and C = specific
heat, then the time constant of a thermocouple is equal to
(a)
(b)
(c)
(d)
Q62. Which one of the following types of trackers uses liquid contained in canisters that
can turn easily into vapour?
(a) Active tracker
(b) Passive tracker
(c) Single-axis tracker
(d) Altitude azimuth tracker
Q63. Viscosity is the property of fluid evolved due to
(a) Resistance offered by the layers of fluid
(b) Resistance offered by the sidewalls of the channel
(c) Spontaneous reactions in the fluid
(d) None of these
Q64. A cube of 1 m side has weight of 2000 N in water. What will be its weight in air (g = 10
m/)?
(a) 9000 N
(b) 1000 N
(c) 12000 N
(d) 10000 N

Q65. A force of 400 N is required to open a process control valve. What is the area of
diaphragm needed for a diaphragm actuator to open the valve with a control gauge
pressure of 50 kPa?
(a) 0.008
(b) .0096
(c) 0.0076
(d) 0.0048

Q66. Pick the correct statement about mechanical pressure of fluid element.
(a) It is a first order tensor and depends upon the orientation of the surface upon which it
acts.
(b) It is a zero-order tensor and does not depend upon the orientation of the surface upon
which it acts.
(c) It is zero order tensor and depends upon the orientation of the surface upon which it
acts.
(d) It is a first order tensor and does not depend upon the orientation of the surface upon
which it acts.
Q67. A horizontal cylinder half filled with fuel has an acceleration of 10 m/. The
gravitational forces are negligible. The free surface of the liquid will be
(a) horizontal
(b) slopes in the direction of acceleration
(c) vertical
(d) slopes in the direction opposite of acceleration

Q68. In a free vortex flow, velocity potential line ( is a function of
(a) angle
(d) velocity
Q69. Frictional losses in the nozzle
(a) reduces the enthalpy of the fluid
(b) increases the enthalpy of the fluid
(c) no effect on enthalpy of the fluid
(d) None of the above
Q70. During MIG welding, metal is transferred in the form of
(a) continuous flow of molten metal
(b) a fine spray of metal
(c) electron beam
(d) solution
Q71. Which of the following is incorrect about the continuous chip formation?
(a) It generates very high frictional heat
(b) It requires low rake angle of cutting tool
(c) It requires ductile material of workpiece
(d) It is difficult to handle
Q72. The chip thickness during slab milling operation is directly proportional to
(a) Cutter’s rotation speed
(b) Angle of contact of tooth
(c) Number of teeth of the cutter
(d) Feed rate of the workpiece

Q73. The abrasive slurry used in ultrasonic machining contains the fine particle of
(a) Aluminium oxide
(b) Boron carbide
(c) Silicon carbide
(d) All of the above
Q74. Which one of the following methods is used for turning external tapers?
(a) Compound rest
(b) Tailstock-offset
(c) Form tool
(d) Taper attachment
Q75. The boundary layer remains attached from the surface during the flow when
(a) and
(b) and
(c) and
(d) and
Q76. Sigma comparator is a type of comparator:
(a) Optical
(b) Electrical
(c) Mechanical
(d) Electronic
Q77. In a vernier caliper, the main scale reads in millimeters with a least count of 0.1 mm.
Ten divisions on the vernier correspond to nine division on the main scale. Determine the
least count of the caliper.
(a) 0.01 mm
(b) 0.001 mm
(c) 0.1 mm
(d) 1 mm
Q78. Tool life is affected mainly with
(a) Feed
(b) Depth of cut
(c) Coolant
(d) Cutting speed
Q79. Recrystallization temperature is one at which
(a) crystals first start forming from molten metal when cooled
(b) new spherical crystals first begin to form the old deformed ones when that strained
metal is heated
(c) the allotropic form changes
(d) crystals grow bigger in size
Q80. In order to get uniform thickness of the plate by rolling process, one provides
(a) Camber on the rolls
(b) Offset on the rolls
(c) Hardening of the rolls
(d) Antifriction bearings
Q81. A four-bar mechanism is as shown in the figure below. At the instant shown, AB is
shorter than CD by 30 cm. AB is rotating at 5 rad/s and CD is rotating at 2 rad/s :

The length of AB is
(a) 10 cm
(b) 20 cm
(c) 30 cm
(d) 40 cm
Q82. Hart mechanism has
Q83. The minimum number of links in a constrained planer mechanism involving revolving
revolute pairs and two higher pairs is:
(a) 3
(b) 4
(c) 5
(d) 6

Q84. Which one of the following mechanisms is an inversion of double slider-crank chain?
(a) Elliptic trammels
(b) Beam engine
(c) Oscillating cylinder engine
(d) Coupling rod of a locomotive
Q85. While designing a cam, pressure angle is one of the most important parameters which
is directly proportional to

(a) pitch circle diameter
(b) prime circle diameter
(c) lift of cam
(d) base circle diameter
Q86. Two shafts A and B are made of the same material. The diameter of shaft B is twice
that of shaft A. the ratio of power which can be transmitted by shaft A to that of shaft B is
_________.
(a) 1/2
(b) 1/4
(c) 1/8
(d) 1/16
Q87. Force F in the given figure equals to

(a) kN
(b) 2 kN
(c) – kN
(d) 3 kN

Q88. A body of mass 5 kg accelerates at a constant rate of on a smooth horizontal surface
due to an external force acting at 30° with horizontal. The magnitude of the force is:
(a) N
(b) N
(c) 10 cos 30° N
(d) 10 sin 30° N
Q89. At what efficiency a machine can be called as an ideal machine?
(a) Between 60 and 70%

(b) Between 70 and 80%
(c) Between 80 and 90%
(d) 100%

Q90. A machine part is designed as a strut, when it is subjected to
(a) an axial tensile stress
(b) an axial compressive stress
(c) a tangential force
(d) any one of the above
Q91. A rubber ball is dropped from a height of 2m. If there is no loss of velocity after
rebounding the ball will rise to a height of
(a) 1 m
(b) 2 m
(c) 3 m
(d) 4 m

Q92. The input which cause a change in inputs-output relationship for either desired input
or interfering inputs or for both are called…….
(a) modifying inputs
(b) modifying outputs
(c) interfering outputs
(d) interfering inputs
Q93. Consider a point on a link connecting double-slider crank chain. It would trace
(a) a circular path
(b) an elliptical path
(c) a straight path
(d) a parabolic path
Q94. Consider the following statements:

1. The increase in metacentric height
2. Increases stability
3. Decreases stability
4. Increases comfort for passengers in a ship
5. Decreases comfort for passengers in a ship
Which of the above statements are correct?
(a) 1 and 3
(b) 1 and 4
(c) 2 and 3
(d) 2 and 4

Q95. A body cooling from 80 to 70 takes 10 minutes when left exposed to environmental
conditions. If the body is to cool further from 70 to 60 under the same external conditions,
it will take
(a) more than 10 minutes
(b) same time of 10 minutes
(c) less than 10 minutes
(d) none of these
Q96. Consider the following facts about thermal diffusivity:
1. unit is
2. it is the relation of k, and .
3. Depends upon temperature
Which of the following are correct?
(a) 1 only
(b) 1 and 2
(c) 2 only
(d) 1, 2 and 3
Q97. A composite wall has two layers of different material having thermal conductivities of
and . If each layer has the same thickness, the equivalent thermal conductivity of the wall
is……….
(a)
(b)
(c)
(d)

Q98. The angle of the diffuser portion of a venturimeter is less than the angle of the
converging portion to:
(a) increase the velocity of flow in the direction of flow at the diverging part
(b) avoid the situation where flow may become compressible
(c) minimize the loss of energy due to flow separation
(d) decrease the velocity of flow in the direction of flow at the diverging part
Q99. Consider the following flow:
1. Developed flow in a pipe
2. Flow of water over a long weir
3. Flow in a long, straight canal
4. The flow of exhaust gases
5. Flow of blood in artery
6. Flow of air around a bullet
7. Flow of air in a tornado
Of the above, which could be modelled as in-viscid flows?
(a) 4, 5
(b) 4, 7
(c) 2, 5
(d) 2, 4
Q100. Consider the following statements:
1. In a given duct system, the total pressure drop varies linearly with flow rate.
2. In a given duct system, the total pressure drop varies in a parabolic manner with flow
rate.
3. For a given flow rate, the total pressure drop of a duct increases as the dampers are
opened more.
4. For a given flow rate, the total pressure drop of a duct is less when the air filters are new.
Of the above, which one is correct?
(a) 1 and 2
(b) 2 and 4
(c) 3 and 4
(d) 1 and 3

## UPPSC Polytechnic Lecturer Mechanical Engineering Solution PDF

The candidates can check UPPSC Polytechnic Lecturer Mechanical Engineering Solution PDF through the direct link given below for the ease of candidates. The solutions are for most expected questions for Mechanical Engineering.