SSC JE MECHANICAL PAPER
1 Define pure
substance ?
- ASubstance which is available in
the purest form in nature
- BSubstance with non-uniform
composition
- CA single substance without any
mixture
- DSubstance with fixed chemical
composition throughout
2 The specific gravity
of water at standard atmospheric conditions is ?
- A1
- Bgreater than 1
- C0
- Dless than 0
3 Which of the
following statements is more relevant?
- AIn the Eulerian method, control
volume approach is not used.
- BIn the Lagrangian approach, a
fluid particle of fixed mass is considered.
- CIn kinematics of fluid flow,
pressure is a vector field.
- DFluid kinematics deals with the
action of the forces in producing or changing motion of fluid.
4 In a triple
fluid vapour absorption refrigeration system, hydrogen gas is used to ?
- Aimprove system performance
- Bcirculate the refrigerant
- Creduce partial pressure of
refrigerant in evaporator
- Dprovide vapour seal
5 In the context of
aircraft refrigeration cycle, what is temperature of air at the exit
of
cooling turbine in the absence of moisture condensation?
- ADry air temperature (DAT)
- BSuper-saturated temperature
- CDry air rated temperature
(DART)
- DSaturated temperature
6 Which of the
following statements is INCORRECT in the context of static fluid pressure?
- AIt exerts force normal to the
walls of the container.
- BIt is independent of shape or
area of the container.
- CIt is directly proportional to
depth of fluid.
- DAt any particular depth. it
changes with direction.
7 The fourth stage of
the compression ignition process is ?
- Aignition delay period
- Bburning on the expansion stroke
- Cperiod of rapid or uncontrolled
combustion
- Dperiod of controlled combustion
8 The refrigerant used
in the VCR based refrigerant cycle rejects heat in _____ ?
- Athe expansion valve
- Bthe condenser
- Cthe compressor
- Dthe evaporator
9 For a Kaplan
turbine, the value of speed ratio is _____ ?
- A0.9
- B0.5
- C0.1
- D2
10 While loading,
_______ material undergoes fracture after large amount of deformation ?
- Aisotropic
- Bplastic
- Cbrittle
- Dductile
11 With respect to the
first law of thermodynamics, which of the following statements is the most
relevant?
- AEnergy can be created or
destroyed depending on the source of input
- BEnergy is always conserved
- CA process that involves
transfer of heat energy is irreversible
- DThere is a natural tendency for
any system to degenerate into a disordered state
12 Which of the
following helps to increase efficiency of the Rankine cycle?
- AIncreasing the condenser pressure
- BIncreasing average temperature
at which heat is rejected from the working fluid
- CIncreasing average temperature
at which heat is transferred to the working fluid
- DOperating at constant
temperature
13 In Lancashire
boilers, the feed water tube is ?
- Athin conduit
- Bopen channel type
- Csolid
- Dperforated
14 A fusible plug must
be used primarily for safety purposes in which of the following types of
boilers ?
- AOil-fired boiler
- BHigh-pressure boiler
- CMarine type boiler
- DFire-tube boiler
15 Which refrigeration
system is driven by low-grade energy?
- ASteam jet refrigeration
- BVortex tube systems
- CGas cycle refrigeration
- DThermo-electric refrigeration
16 In the context of
fluid mechanics, which of the following statements is INCORRECT?
- AFluid cannot sustain any shear
stress when at rest.
- BFluid continues in motion under
the application of shear stress.
- CFluid does not deform
continuously under shear stress.
- DFluid deforms under very small
shear stress.
17 For a static fluid,
the increase of pressure at any point inside the fluid, in a vertically
downward direction, must be equal to the product of the of the fluid and depth
from the free surface ?
- Aspecific gravity
- Bdensity
- Cviscosity
- Dspecific weight
18 Which of the
following is the working fluid in an air-cycle refrigeration system?
- ASaturated air
- BCompressed air
- CAir at high Mach number
- DGas
19 The benchmark
pressure above which a boiler is considered to be a high- pressure boiler is ?
- A70 bar
- B60 bar
- C80 bar
- D50 bar
20 Which of the
following is NOT considered as external loads?
- AThose arising from fluid
pressure
- BThose arising from service
conditions
- CThose arising from cohesion of
material
- DThose arising from environment
21 ______ is also
called spheroidal graphite cast iron ?
- ADuctile cast iron
- BMalleable cast iron
- CWhite cast iron
- DGray cast iron
22
For a carburising
flame, the flow of ______ is kept higher ?
- Aargon
- Bnitrogen
- Coxygen
- Dacetylene
23 Under what
condition of fluid flow does shear stress NOT exist?
- ARelative motion exists between
fluid layers
- BFluid in low velocity motion
- CNegligible viscosity
- DFluid in high velocity motion
24 Another name for
the Bell-Coleman cycle is ?
- ACarnot cycle
- Breversed Carnot cycle
- Cideal reverse Brayton cycle
- DRankme cycle
25 With respect to
reaction turbines, which of the following statements is relevant?
- AGoverning of reaction turbines
is done by altering position of the guide vanes.
- BFlow rate cannot be controlled
by changing the gate openings to the runner.
- CWater does not flow through a
scroll casing.
- DGuide blades are not connected
to the regulating ring.
26 Which of the
following is the best example of a thixotropic fluid?
- AToothpaste
- BMinerals in suspension
- CFly ash
- DPrinting ink
27 What happens when a
fluid is at rest?
- AFrictional force is present
- BInternal deformation is
considerable
- CFluid element will not be
subjected to normal and shear component
- DThere is no shear component
28 Nominal volume
generated by the working piston when travelling from one dead centre to the
next is called ?
- Aclearance volume
- Bswept volume
- Ctotal volume
- Dstroke volume
29 What is the unit of
surface tension?
- AN/m
- Bkg/m
- CN
- DN-m
30. Aircraft engines use
________ for cooling engines ?
- Aan air-cooled system
- Ba thermo-syphon cooling system
- Ca water-cooled system
- Da forced cooling system
31 Which of the
following characteristics of a centrifugal pump is vital?
- ASlip will decrease with the increase
in flow rate
- BThere will be no whirl
component of velocity at the entry to impeller
- CFluid is considered to have
friction while flowing inside the pump
- DFluid moves normal to the blade
32 What is radiant
heating in the context of boilers?
- AHeating process carried out
using radiation effect
- BSaturated steam is
re-circulated and super-heated
- CHeating done on external walls
only by reflecting radiant energy
- DHeating done on radial tubes
33 An appurtenance
whose length generally does NOT exceed three times of its diameter is called ?
- Aan orifice
- Ba diffuser
- Ca non-return valve
- Da mouthpiece
34. In actual
compressors, there is a clearance between the cylinder head and piston to take
care of thermal expansion. Identify the correct expression from the given
options, where C is the clearance (in mm) and L is the stoke length (in mm) ?
- AC = (0.005L + 0.5)
- BC = (0.05L + 0.05)
- CC = (0.005 + 0.5L)
- DC = (0.05L + 0.5)
35. The major function
of a steam nozzle is to ?
- Aproduce low viscosity steam
- Bproduce low velocity jet of
steam
- Cproduce high viscosity steam
- Dproduce high velocity jet of
steam
36. A member of length
200 mm and diameter 25 mm is subjected to a tensile load of 20 kN. The final
length of the member is found to be 220 mm. The percentage increase in the
length of the member is ?
- A1%
- B10%
- C5%
- D20%
37. At sea level,
under normal conditions, what is the atmospheric pressure?
- A104.013 kPa
- B100.043 kPa
- C101.32 kPa
- D100.1 kPa
38. How is a
high-pressure boiler classified?
- AWhen it operates, high amount
of steam is required for the operation of the cycle
- BWhen pressure > 50 bar
- CWhen velocity of water is very
low
- DWhen pressure > 80 bar
39 Which of the
following does NOT result in poor performance of boilers?
- APoor combustion
- BSurface fouling
- CPoor water quality
- DBoiler mounting
40. Which is the most
practical fluid for the Rankine cycle?
- AFuel
- BAir
- CAir-fuel mixture
- DWater
41. What is a
dilatant?
- AIt is a shear thickening fluid.
- BIt is a fluid with suspended
colour pigments.
- CIt is a fluid that sustains
shear stress without ally deformation.
- DIt is a shear thinning fluid
42. According to
Kelvin-Planck’s statement of the second law of thermodynamics, which of the
following statements is correct?
- AIt restricts the thermal
efficiency of the heat engine to be lesser than unity.
- BHeat from a source should be
rejected to a high temperature sink.
- CIt restricts the mechanical
efficiency of the heat engine to be lesser than unity.
- DThermal efficiency of the heat
engine will be unity.
43. Fans and blowers
of turbo machines ?
- Aa higher static pressure will
prevail
- Bdeliver air at a higher desired
velocity
- Cdeliver air at a lower mass
flow rate
- Dspiral casing decreases the
static pressure
44. What is the
function of a fly wheel in IC engines?
- ATo absorb energy during suction
stroke
- BTo maintain constant speed
- CTo increase the speed
- DTo circulate air in the engine
for cooling
45. What is a gauge
pressure?
- AIt is pressure measured
relative to local atmospheric pressure.
- BIt is an alternate name of
datum pressure.
- CIt is the same as local
atmospheric pressure.
- DIt is pressure measured
relative to a perfect vacuum.
46. Which of the
following is an inferential type of flow meter?
- ARotameter
- BMagnetic flowmeter
- CLaser doppler
- DPurge flow regulator
47. A single stage impulse
turbine is also known as ?
- Ade Laval turbine
- BCurtis stage turbine
- Creaction turbine
- DRateau turbine
48. _______ is the
ability of steel to resist stresses that are reversal in nature ?
- AImpact strength
- BToughness
- CHardness
- DFatigue strength
49. Which of the
following statements is correct with reference to perpetual motion machines of
the first kind?
- AIt violates the second law of
thermodynamics.
- BIt produces heat without
receiving work input.
- CIt produces work without
receiving heat.
- DIt is a reversible process.
50. In a
flow-measuring device, what is velocity head?
- AFree rise of liquid column in
an open-ended rube
- BDifference in elevation in the flow
direction
- CVertical distance through which
a column of the flowing liquid would rise in an open-ended tube
- DFree fall of liquid column to
attain a given velocity freely
51 For a single
cylinder four-stroke oil engine, indicated power is 15 kW. calorific value of
fuel is 40000 kJ/kg and fuel consumed is 0.001 kg/s. What will be the indicated
thermal efficiency?
- A62.5%
- B40%
- C75%
- D37.5%
52 Identify the
requirement of a good boiler from the following options ?
- AIt should have more flexible
joints.
- BIt should be light in weight
and compact.
- CIt should be able to produce
steam at minimum pressure.
- DIt should use maximum
refractory material.
53 Which of the
following statements is INCORRECT with reference to the first law of
thermodynamics?
- AEnergy transfer to a system
from its surroundings is a positive quantity
- BWork done by a system on its
surroundings is a positive quantity
- CHeat interaction is a path
function
- DEnergy transfer is a point
function
54 In air standard
cycle analysis of IC engines, which of the following statements is correct?
- ASpecific heats (Cp, Cv) of air
vary with temperature.
- BThere will be a sudden change
in chemical equilibrium of the working fluid.
- CThere are no intake or exhaust
processes.
- DCompression and expansion
processes are considered as irreversible
55 When water is about
to vapourise it is called?
- Asub-cooled liquid
- Bsuper-heated vapour
- Csaturated vapour
- Dsaturated liquid
56 Which of the
following statements is more relevant in the context of IC engines?
- ACompression Ignition (CI)
engines have lesser weight than SI engines.
- BCompression ratio for air is in
the range of 16 to 20 for SI engines.
- CWalls of the engine cylinder of
SI engines need to be thicker than CI engines.
- DCompression ratio of the
fuel-air mixture is in the range of 6 to 10 in Spark Ignition (SI)
engines.
57 The COP
(coefficient of performance) of a heat pump is always _______ the COP of a
refrigerator ?
- Aless than or equal to
- Bgreater than
- Cless than
- Dequal to
58 A thermoelectric
refrigeration system requires ?
- Alow voltage AC
- Blow voltage DC input
- Chigh voltage AC input
- Dhigh voltage DC input
59 In a compressor,
work is done by ?
- Athe rotor on the fluid element
- Ba static component known as
impeller
- Cthe fluid on the rotor
- Dthe rotating part called stator
60 Under what
condition is an inclined manometer used?
- AWhen u-tube manometer is not
available
- BWhen surface of measurement is
inclined
- CIn high pressure range
- DIn small pressure changes
61 With respect to
head loss of flowing fluid, select the most appropriate statement ?
- AIncrease in velocity in a flow
induces large-scale turbulence
- BEnergy loss is nor caused by
change in velocity
- CEnergy loss is not due to
formation of eddies
- DPortion of energy loss will not
be dissipated as heat
62 Which of the
following pairs is NOT an example of a lower pair?
- APrismatic pair
- BHelical and cylindrical pair
- CRevolute pair
- DRolling ball on a flat surface
63 In the context of
the Reynolds transport theorem, which of the following statements is the most
appropriate?
- AIt uses deforming control
volume.
- BIt links system and control
volume approaches.
- CIt uses fixed control volume.
- DIt does not use control volume
approach.
64 If compression is
achieved by trapping a refrigerant vapour in an enclosed space and then reducing
its volume, then it is called ?
- Aradial-flow type compressor
- Bpositive-displacement type
compressor
- Copen type compressor
- Droto-dynamic type compressor
65 Which of following
is NOT a phase in steel?
- AAustenite
- BMartensite
- CLimonite
- DPearlite
66 Which of the
following is NOT a projectile motion?
- AA bullet fire d from a gun
- BA stone thrown in any direction
- CA stone thrown horizontally
from a building
- DA car moving in a straight line
67 In isentropic
compression, similar to aircraft refrigeration cycle, what is ram efficiency?
- ARatio of input to output ram
pressure
- BIt is proportional to mass flow
rate
- CRatio of actual pressure rise
to isentropic pressure
- DRatio of aircraft velocity to
sonic velocity
68 Define a machine in
terms of its basic objective ?
- AA device to transform force.
- BA device to transfer load to
source.
- CA device used to transfer
force.
- DA device to transfer and
transform motion and force from source to load.
69 What is the unit of
absolute viscosity?
- ACentipoise
- BSaybolt universal unit
- CCentistoke
- DViscosity index
70 Identify the method
by which steel is NOT classified ?
- AManufacturing method
- BBased on notch toughness
- CBased on heat treatment
- DBased on chemical composition
71 Which of the
following is NOT a water-tube boiler?
- ALaMont boiler
- BLoeffler boiler
- CStirling boiler
- DCornish boiler
72 What is a diffuser?
- AIt is a type of nozzle
- BIt is voltage regulator
- CIt is a type of valve that
decreases pressure
- DIt is a duct which decreases
the velocity and increases pressure.
73 What is the flow
called if the velocity at a given instant is the same in both magnitude and
direction throughout the flow domain?
- ALaminar flow
- BSteady flow
- CTurbulent flow
- DUniform flow
74 An ideal constant
pressure gas turbine works on the ________ cycle ?
- AStirling
- BLenoir
- CBrayton
- DAtkinson
75 The air fuel ratios
used in a compression ignition engine lie in the range of ?
- A18 to 25
- B6 to 14
- C40 to 48
- D28 to 36
76 Which of the
following statements is INCORRECT with respect to water rube boilers?
- AThey are smaller and lesser in
weight
- BThey are suitable for high
steam pressure
- CThey cannot handle high steam
pressure
- DThey are suitable for large gas
flows
77 In the context of
moving control volume, which of the following statements is more relevant?
- AAbsolute velocity of fluid
carries fluid a cross the control volume
- BDifference between absolute and
relative velocities of fluid is the velocity across moving control volume
- CControl volume is considered as
a fixed volume in space
- DRelative velocity of fluid
carries fluid across the control surface of moving control volume
78 _______ states that “pressure of a gas
mixture is equal to the sum of the pressures each gas would exert if it existed
alone at the mixture temperature and volume” ?
- ADalton’s law of additive
pressures
- BIdeal gas law
- CHooke’s law
- DAmagat’s law of additive
volumes
79 Lithium bromide is
used as an absorbent in _______ ?
- AElectrolux refrigerators
- Bsteam jet refrigeration
- Cvapour absorption refrigeration
- Dvapou compression refrigeration
80 A continuity
equation for two dimensional compressible flow is given by ?
- A
- B
- C
- D
81 Which of the
following links does NOT undergo any deformation while transmitting motion?
- AResistance link
- BFlexible link
- CRigid link
- DFluid link
82 Identify the
complete and correct statement of the first law of thermodynamics ?
- AWhen a closed system executes a
complete cycle, the sum of heat interactions is equal to the sum of work
interactions.
- BWhen a system undergoes a
cycle, the integral of heat is equal to the integral of work.
- CDifference between the heat and
work interactions during a process, which is property of the system.
- DDuring a process, extracting
work without supplying heat, while sacrificing the energy of the system.
83 Which of the
following is the characteristic of an isochoric process?
- AProcess during which no mass is
transferred
- BProcess during which specific
volume remains constant
- CProcess applied to impure
substances
- DProcess during which no heat is
transferred
84 Which of the
following statements is relevant?
- AFluid deforms under constant
shear stress.
- BFluid can sustain shear stress
when at rest.
- CFluid deforms continuously
under the action of shear stress of even very low magnitude.
- DFluid does not deform
continuously under the action of shear stress.
85 Heat and work both
are ?
- Apoint functions
- Bpoint and path functions both
- Cpath functions
- Dstate functions
86 With respect to the
term kinematic viscosity, which of the following statements is more relevant?
- AIt is an indicator of absolute
tendency of the fluid.
- BDenominator represents physical
property of the fluid to maintain its momentum.
- CDenominator represents
propagation of disturbance.
- DNumerator represents property
of the fluid to maintain its momentum.
87 What is a
degree-of-freedom in the context of kinematics?
- AMaximum independent coordinates
to describe the configuration
- BMinimum dependent coordinates
to describe the configuration
- CMinimum independent variables
specified to fix the configuration
- DMaximum dependent variables
specified to describe the configuration.
88 Which of the
following is NOT a maintenance method of a boiler?
- AShort-term lay-up
- BChemical lay-up
- CDry lay-up
- DWet lay-up
89 Define strain
energy ?
- AIt refers to change in length
of a ball.
- BIt refers to external work done
on a bar.
- CIt is the potential energy stored
by an elastic body when deformed
- DIt is the energy released by a
bar during loading process.
90 According to IBR
regulations, boilers exceeding _______ need regular inspection and
certification ?
- Acapacity of more than 15 litres
- Bcapacity of more than 50
gallons
- Ccapacity of more than 5 gallons
- Dcapacity lesser than 5 gallons
91 A centrifugal pump
?
- Aflow is radially outwards in
this pump
- Bworks on the same principle as
that of a Francis turbine
- Cfluid gain is through constant
head
- Dflow is tangential in this pump
92 Intercooling in
multistage compression reduces __ ?
- Athe volume of free air
delivered
- Bthe work input to compressor
- Cthe pressure of air at delivery
- Dthe index of compression
93 Boilers in the
Rankine cycle are used ?
- Ato maintain heat in the process
- Bto store working fluid
- Cto allow expansion of steam
- Dfor steam generation
94 The Rankine cycle
is an ideal cycle for vapour power plants because?
- Ait does not allow isentropic
expansion
- Bit includes reversible
processes
- Cwater enters the pump at
unsaturated state
- Dsteam is not condensed in the
condenser
95 The compression
ratio of a Compression Ignition (CI) engine is ?
- A< 5
- B12 to 22
- C5 to 10
- D10 to 15
96 Why do engines need
to be cooled?
- ATo regulate mass transfer
- BTo improve compression volume
- CTo reduce ignition temperature
- DTo avoid pre-ignition and
knocking
97 Select the most
appropriate definition of a turbine from the following statements ?
- AIt is a device where mechanical
energy from moving parts is transferred to a fluid.
- BIt is device in which kinetic
energy held by a fluid is converted to mechanical energy of a rotating
member.
- CIt is a device where potential
energy is transferred to a fluid.
- DTurbine is a fluid machine.
98 One ton of refrigeration
is equal to _______ kW ?
- A1
- B3.5
- C2.5
- D5
99 The Lagrangian
description of fluid field is more computational because ?
- Avelocity field is a continuous
function distribution with position and time
- Bvariation of velocity is
expressed in Cartesian coordinates
- Cit is required to track
movement of a large number of fluid particles with time
- Dvelocity of the fluid particle
is the same as the local velocity
100 What is sonic
speed?
- AIt is the speed at which
disturbance propagates through a medium.
- BIt is the speed of air.
- CIt is the speed at which disturbance
propagates at higher velocity.
- DIt is the speed at which
disturbance propagates through an inelastic medium.
SSC JE 2020 : Mechanical Engineering - Previous Years Solved Papers (2008-19)
SSC-JE 2021 MECHANICAL ENGINEERING PREVIOUS YEARS TOPIC WISE OBJECTIVE DETAILED SOLUTION WITH THEORY
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