Full-Length Mock Test 6 — RRB JE CBT 2 Technical Abilities Pattern (100 MCQs)

Section A: Engineering Mechanics and Strength of Materials (20 Questions)

1. A couple is defined as a system of two:
   (a) Equal, parallel, opposite forces whose lines of action do not coincide (b) Equal, collinear forces acting in the same direction (c) Unequal, non-parallel forces acting at a single point (d) Forces of zero magnitude acting anywhere
2. The moment of a couple is independent of the:
   (a) Point about which it is taken (b) Magnitude of either force (c) Perpendicular distance between the forces (d) Direction of rotation it produces
3. The condition for equilibrium of a rigid body under a system of parallel coplanar forces requires the sum of forces and the sum of:
   (a) Moments about any point to both be zero (b) Only velocities to be zero, with no moment condition (c) Only accelerations to be zero, with no moment condition (d) Only masses to be zero, with no force or moment condition
4. Angle of repose of a body on an inclined plane is the angle at which the body is:
   (a) On the verge of sliding under its own weight (b) Completely at rest with zero friction present (c) Moving at maximum possible acceleration (d) Undergoing pure rotation with no translation
5. The radius of gyration of a body about an axis relates its moment of inertia to its:
   (a) Mass (b) Volume only, with no mass relation (c) Surface area only (d) Density only, with no mass relation
6. D'Alembert's principle allows a dynamics problem to be converted into an equivalent problem of:
   (a) Static equilibrium, by introducing an inertia force (b) Pure thermodynamics, with no mechanical basis (c) Pure fluid flow, with no solid mechanics basis (d) Pure electrical circuit analysis
7. Impulse of a force is defined as the product of force and:
   (a) Time for which it acts (b) Displacement produced (c) Mass of the body (d) Velocity of the body squared
8. The impulse-momentum principle states that impulse equals the:
   (a) Change in momentum (b) Change in kinetic energy (c) Change in potential energy (d) Total work done, regardless of momentum change
9. Poisson's ratio for most engineering metals typically lies in the range of approximately:
   (a) 0.25 to 0.35 (b) 1.5 to 2.0 (c) −1.0 to −0.5 (d) 5.0 to 10.0
10. A member subjected to a combination of direct stress and bending stress experiences a resultant stress equal to the:
    (a) Algebraic sum of the direct and bending stresses at a given point (b) Direct stress alone, with no bending contribution ever considered (c) Bending stress alone, with no direct stress contribution ever considered (d) Product of direct and bending stress values
11. The elastic limit of a material is the stress up to which the material:
    (a) Returns to its original shape upon removal of load (b) Remains permanently deformed even after load removal (c) Fractures immediately upon any loading (d) Exhibits no stress-strain relationship at all
12. The ultimate tensile strength of a material corresponds to the:
    (a) Maximum stress reached on the engineering stress-strain curve (b) Stress at the elastic limit only (c) Stress at zero strain (d) Stress at the point of first yielding only, with no further increase possible
13. Necking in a ductile tensile specimen refers to:
    (a) Localized reduction in cross-sectional area prior to fracture (b) Uniform elongation along the entire gauge length with no localization (c) An increase in cross-sectional area prior to fracture (d) A phenomenon exclusive to brittle materials
14. A fixed beam (both ends built-in) generally has, compared to a simply supported beam of the same span and loading, a:
    (a) Lower maximum bending moment (b) Higher maximum bending moment always (c) Identical bending moment distribution in every case (d) Zero bending moment throughout
15. The shear force at any section of a beam equals the:
    (a) Algebraic sum of vertical forces on one side of that section (b) Total length of the beam (c) Total distributed load over the entire span regardless of section location (d) Product of the bending moment and the distance from the support
16. The relationship between shear force (V), bending moment (M), and position (x) along a beam is given by:
    (a) dM/dx = V (b) dV/dx = M (c) M = V × constant regardless of x (d) V and M are unrelated
17. A composite (compound) bar of two materials sharing a common load in parallel experiences:
    (a) Equal strain but generally different stress in each material (proportional to their moduli) (b) Equal stress but different strain in each material (c) Neither equal stress nor equal strain under any condition (d) Zero stress in both materials regardless of load
18. The strength of a riveted joint is assessed against tearing of the plate, shearing of the rivet, and:
    (a) Crushing of the plate/rivet material (b) Only thermal degradation, with no mechanical failure mode (c) Only magnetic failure, with no mechanical failure mode (d) Only electrical failure, with no mechanical failure mode
19. Bending stress in a beam varies:
    (a) Linearly with distance from the neutral axis (b) Uniformly throughout the cross-section regardless of distance from the neutral axis (c) Inversely with distance from the neutral axis (d) Only at the outer edges, with zero variation elsewhere
20. Slenderness ratio of a column influences whether it fails by:
    (a) Buckling (long column) or crushing (short column) (b) Only crushing, regardless of slenderness (c) Only buckling, regardless of slenderness (d) Neither buckling nor crushing under any condition

Section B: Thermodynamics, IC Engines, and Power Plant Engineering (20 Questions)

21. A working substance undergoing a thermodynamic cycle returns, at the end of the cycle, to its:
    (a) Initial state (b) A completely different, unrelated state (c) A state of zero pressure regardless of starting conditions (d) A state of zero temperature regardless of starting conditions
22. Specific volume of a substance is defined as:
    (a) Volume per unit mass (b) Mass per unit volume (c) Volume per unit time (d) Mass per unit time
23. Enthalpy of a system is defined as internal energy plus the product of:
    (a) Pressure and volume (b) Temperature and entropy (c) Mass and specific heat (d) Force and displacement
24. A steady flow energy equation (SFEE) applied to a turbine typically neglects, for a first approximation, changes in:
    (a) Potential energy (compared to enthalpy and kinetic energy changes) (b) Enthalpy entirely, considering only potential energy (c) Mass flow rate entirely, treating it as always zero (d) Time entirely, treating the process as instantaneous with no duration
25. The heat rejected by a heat engine operating on a cycle, according to the First Law over a complete cycle, equals:
    (a) Heat supplied minus net work done (b) Heat supplied plus net work done (c) Zero, always, regardless of heat supplied or work done (d) Net work done alone, with no relation to heat supplied
26. A refrigerator, viewed thermodynamically, is a device that:
    (a) Transfers heat from a cold body to a hot body with the aid of external work (b) Transfers heat spontaneously from hot to cold with no external work required (c) Converts heat completely into work with no rejection (d) Operates without any heat transfer at all
27. The COP of a refrigerator is defined as the ratio of:
    (a) Heat extracted from the cold body to the net work input (b) Net work input to heat extracted from the cold body (c) Heat rejected to the hot body to heat extracted from the cold body (d) Heat rejected to the hot body to net work input
28. The COP of a heat pump is defined as the ratio of:
    (a) Heat delivered to the hot body to the net work input (b) Heat extracted from the cold body to the net work input (c) Net work input to heat delivered to the hot body (d) Heat extracted from the cold body to heat delivered to the hot body
29. For the same operating temperatures, the COP of a heat pump is related to the COP of a refrigerator by:
    (a) COP(heat pump) = COP(refrigerator) + 1 (b) COP(heat pump) = COP(refrigerator) − 1 (c) COP(heat pump) = COP(refrigerator) (d) COP(heat pump) = 1/COP(refrigerator)
30. An air-standard Otto cycle's efficiency increases with increasing:
    (a) Compression ratio (b) Cut-off ratio only, with no dependence on compression ratio (c) Ambient pressure only, with no dependence on compression ratio (d) Engine's physical weight only
31. A Stirling engine operates on a cycle that ideally includes two isothermal and two constant:
    (a) Volume processes (b) Pressure processes (c) Entropy processes exclusively, matching the Carnot cycle exactly (d) Enthalpy processes only, with no other process type
32. The Brayton cycle, used as the basis for gas turbine analysis, consists of two isentropic and two constant:
    (a) Pressure processes (b) Volume processes (c) Temperature processes (d) Entropy processes, making all four processes isentropic
33. Combustion in a boiler furnace requires an adequate supply of:
    (a) Air (oxygen) mixed with the fuel in appropriate proportion (b) Only fuel, with no air or oxygen required at all (c) Only water, with no fuel or air required (d) Only an electrical spark, with no fuel or air required
34. Excess air supplied to a boiler furnace beyond the theoretical (stoichiometric) requirement is used primarily to:
    (a) Ensure more complete combustion of the fuel (b) Reduce combustion efficiency deliberately (c) Eliminate the need for any fuel at all (d) Increase unburnt fuel losses deliberately
35. The calorific value of a fuel represents the:
    (a) Heat energy released per unit mass (or volume) of fuel upon complete combustion (b) Total mass of the fuel available (c) Colour of the flame produced during combustion (d) Total volume of air required for combustion
36. Higher calorific value (HCV) of a fuel, compared to lower calorific value (LCV), includes the:
    (a) Latent heat of the water vapour formed during combustion (b) Sensible heat of the flue gases only (c) Heat lost to the surroundings only, with no relation to water vapour (d) Heat absorbed by the boiler's structural material only
37. A cooling tower rejects heat from the condenser cooling water primarily through:
    (a) Evaporative cooling as water contacts a stream of air (b) Direct electrical resistance heating in reverse (c) Nuclear reaction with the surrounding air (d) Chemical reaction with the surrounding air
38. Load factor of a power plant is defined as the ratio of average load to:
    (a) Maximum (peak) load over a given period (b) Installed capacity only, with no relation to peak load (c) Minimum load only, with no relation to peak or average load (d) Zero load conditions exclusively
39. Base load power plants are typically designed to operate:
    (a) Continuously at a relatively constant, high output (b) Only during short peak demand periods (c) Only at zero load, never generating power (d) Only when renewable sources are unavailable, with no other operating condition
40. Peak load power plants, in contrast to base load plants, are designed for:
    (a) Quick start-up and operation only during periods of high demand (b) Continuous, constant operation at all times with no variation (c) Operation exclusively at night, never during the day (d) Operation only once per year

Section C: Theory of Machines and Machine Design (20 Questions)

41. A single slider-crank chain is the basis of the mechanism found in:
    (a) A reciprocating IC engine (b) A simple pendulum clock exclusively (c) A pure rotary pump with no reciprocating element (d) A stationary structural truss
42. The Grashof's law for a four-bar mechanism states that for at least one link to make a complete revolution relative to another, the sum of the shortest and longest link lengths must be:
    (a) Less than or equal to the sum of the two intermediate link lengths (b) Greater than the sum of the two intermediate link lengths in every case (c) Equal to zero (d) Unrelated to the other two link lengths
43. A Scotch yoke mechanism converts rotary motion into:
    (a) Simple harmonic (sinusoidal) reciprocating motion (b) Uniform velocity reciprocating motion with no variation (c) Purely rotary motion at a different fixed speed, with no reciprocating output (d) No motion at all, as it is a static structure
44. The addendum circle of a gear passes through the:
    (a) Tips of the gear teeth (b) Roots of the gear teeth (c) Exact centre of the gear (d) Base circle only, with no relation to tooth tips
45. The dedendum circle of a gear passes through the:
    (a) Roots of the gear teeth (b) Tips of the gear teeth (c) Exact centre of the gear (d) Outer casing only, with no relation to tooth roots
46. The base circle of an involute gear is the circle from which the:
    (a) Involute tooth profile is generated (b) Gear's outer casing is measured, with no relation to the tooth profile (c) Gear's weight is calculated (d) Gear's colour code is determined
47. Contact ratio in gear meshing represents the:
    (a) Average number of teeth pairs in contact at any instant during meshing (b) Total number of teeth on both gears combined (c) Ratio of gear module to pressure angle (d) Ratio of gear weight to gear diameter
48. A higher contact ratio in gear design generally results in:
    (a) Smoother, quieter operation with load shared among more tooth pairs (b) Rougher, noisier operation with load concentrated on fewer teeth (c) No change in operational smoothness whatsoever (d) Complete elimination of any load transmission capability
49. The efficiency of a screw jack (or power screw) depends significantly on the:
    (a) Helix angle of the thread and the coefficient of friction (b) Colour of the screw material only (c) Ambient humidity only, with no relation to thread geometry or friction (d) Length of the handle only, with no relation to thread geometry
50. A self-locking screw jack is one in which the:
    (a) Load cannot descend on its own once the applied effort is removed (b) Load always descends immediately upon effort removal, regardless of thread angle (c) Screw thread has zero friction (d) Screw thread cannot rotate under any applied torque
51. The efficiency of a machine (mechanical advantage device) is defined as the ratio of:
    (a) Output work (or power) to input work (or power) (b) Input work to output work (c) Mechanical advantage to velocity ratio directly, with no work/power comparison (d) Velocity ratio to mechanical advantage directly, with no work/power comparison
52. Mechanical advantage of a simple machine is defined as the ratio of:
    (a) Load lifted to effort applied (b) Effort applied to load lifted (c) Distance moved by the load to distance moved by the effort (d) Time taken by the load to time taken by the effort
53. Velocity ratio of a simple machine is defined as the ratio of:
    (a) Distance moved by the effort to distance moved by the load (b) Load lifted to effort applied (c) Effort applied to load lifted (d) Output power to input power directly, with no distance comparison
54. A gear train's overall efficiency is generally reduced by:
    (a) Friction losses at each meshing gear pair and bearing (b) Increasing the number of idler gears with no other change, having zero effect on efficiency (c) Reducing the applied load to exactly zero (d) Operating at exactly zero speed
55. The design of a coupling for connecting two shafts must accommodate the transmitted torque and any:
    (a) Misalignment between the shafts (b) Change in the shafts' material colour (c) Change in ambient humidity, with no relation to torque or alignment (d) Change in the shafts' manufacturing date
56. A leaf spring's flexibility (and hence its ability to absorb shock) is influenced by the number, length, and thickness of its:
    (a) Individual leaves (b) Bolts used to clamp the assembly only (c) Mounting brackets only (d) Paint layers only
57. The Wahl correction factor applied to helical spring stress calculations accounts for:
    (a) Curvature effects and direct shear stress in the coiled wire (b) Only the spring's overall colour, with no stress-related significance (c) Only the spring's manufacturing cost (d) Only the ambient temperature, with no relation to spring geometry
58. A universal joint (Hooke's joint), when transmitting motion between two non-parallel, intersecting shafts, produces an output angular velocity that is:
    (a) Non-uniform (fluctuating) even for a constant input angular velocity (b) Always exactly identical to the constant input angular velocity, with no fluctuation (c) Always zero, regardless of input speed (d) Independent of the shaft angle between the two shafts
59. A flexible coupling, compared to a rigid coupling, is preferred where the connected shafts have:
    (a) A small amount of angular, parallel, or axial misalignment (b) Perfect, zero misalignment in every case (c) No torque to transmit at all (d) Identical rotational speed at all times with no possible variation
60. The design life of a rolling contact bearing is most sensitive to changes in the:
    (a) Applied load (due to the inverse power-law relationship with life) (b) Bearing's paint colour (c) Manufacturer's brand name only (d) Ambient lighting conditions in the installation area

Section D: Fluid Mechanics, Manufacturing, Metrology, Heat Transfer, and Material Science (20 Questions)

61. The equation of continuity for an incompressible fluid in steady flow states that the:
    (a) Product of cross-sectional area and velocity remains constant along the flow path (b) Pressure remains constant along the entire flow path regardless of area (c) Velocity remains constant regardless of any change in cross-sectional area (d) Density varies significantly along the flow path
62. A Pitot tube is used to measure:
    (a) Local flow velocity, based on the difference between stagnation and static pressure (b) Only fluid temperature (c) Only fluid viscosity directly (d) Only fluid colour/turbidity
63. An orifice meter, similar in principle to a Venturi meter, is used to measure:
    (a) Flow rate, based on the pressure drop across a constriction (b) Only fluid density directly (c) Only fluid boiling point (d) Only fluid freezing point
64. A positive displacement pump, unlike a centrifugal pump, delivers fluid by:
    (a) Physically trapping and displacing a fixed volume of fluid per cycle (b) Imparting kinetic energy via a rotating impeller, exactly like a centrifugal pump (c) Using only gravitational flow, with no pumping mechanism (d) Using only evaporation and condensation, with no mechanical displacement
65. The specific speed of a turbine (or pump) is a parameter used primarily to:
    (a) Classify and select the appropriate type of turbine/pump for given conditions (b) Measure the exact colour of the working fluid (c) Measure only the ambient temperature at the installation site (d) Measure only the electrical output voltage, with no relation to the fluid machine's design
66. Broaching is a machining process that uses a multi-tooth cutting tool to remove material in a:
    (a) Single linear pass (b) Continuous rotary motion only, with no linear pass involved (c) Purely thermal process with no cutting tool at all (d) Purely chemical etching process with no mechanical cutting
67. Electric discharge machining (EDM) removes material through:
    (a) Controlled electrical sparks eroding the workpiece (b) Direct mechanical cutting with a rotating tool, identical to milling (c) Purely chemical dissolution with no electrical involvement (d) Purely thermal melting from an external flame source
68. Investment casting (lost-wax process) is particularly suited for producing:
    (a) Intricate, precise components with fine surface finish (b) Only extremely large, low-precision components (c) Only components with no internal cavities of any kind (d) Only components made from non-metallic materials exclusively
69. Die casting is a manufacturing process typically used for producing large quantities of parts from:
    (a) Low-melting-point alloys such as aluminium, zinc, or magnesium (b) Only extremely high-melting-point ceramics (c) Only wood, with no metal involved (d) Only paper products
70. A go/no-go gauge's "no go" end is designed so that it should:
    (a) Not enter (or pass) if the component is within tolerance (b) Always enter (or pass) regardless of the component's actual size (c) Never be used in any inspection process (d) Only measure temperature, with no dimensional function
71. Thermal conductivity of a material expresses its ability to:
    (a) Conduct heat, per Fourier's law (b) Conduct electricity exclusively, with no relation to heat (c) Resist magnetic fields exclusively (d) Change colour with temperature
72. A shell-and-tube heat exchanger's effectiveness is influenced by the flow arrangement, being generally higher for a:
    (a) Counter-flow arrangement compared to parallel flow (b) Parallel-flow arrangement compared to counter-flow, in every case (c) Cross-flow arrangement exceeding both parallel and counter-flow in every case, with no exception (d) Arrangement with zero flow on either side
73. The vapour compression refrigeration cycle's compressor primarily serves to:
    (a) Raise the pressure (and temperature) of the refrigerant vapour (b) Lower the pressure of the refrigerant vapour (c) Condense the refrigerant into liquid directly, with no pressure change (d) Absorb heat from the space being cooled directly, with no compression role
74. Martensite, formed during the hardening (quenching) of steel, is characterised by being:
    (a) Very hard but brittle (b) Very soft and highly ductile (c) Completely non-magnetic under all conditions (d) Identical in properties to annealed steel
75. Case hardening processes are particularly suited to components requiring:
    (a) A hard, wear-resistant surface with a tough core (b) Uniform hardness throughout with no distinction between surface and core (c) Complete absence of any hardness at all (d) A surface coating of a non-metallic material only, with no core hardness requirement
76. Fibre-reinforced polymer composites generally offer, compared to conventional metals, less:
    (a) Ductility and toughness, along with more complex manufacturing/repair (b) Strength-to-weight ratio, being inferior to metals in every case (c) Stiffness-to-weight ratio, being inferior to metals in every case (d) Corrosion resistance, being inferior to metals in every case
77. The efficiency of a boiler generally decreases with:
    (a) Increasing flue gas heat losses (b) Decreasing flue gas heat losses (c) Increasing feedwater temperature only, with no relation to flue gas losses (d) Decreasing fuel consumption only, with no relation to flue gas losses
78. A slip gauge's extremely flat, precisely finished surfaces allow multiple gauges to be combined by a technique called:
    (a) Wringing (b) Welding (c) Riveting (d) Brazing
79. In refrigeration terminology, "sub-cooling" of the liquid refrigerant leaving the condenser refers to cooling it:
    (a) Below its saturation temperature at that pressure (b) Above its saturation temperature at that pressure (c) To exactly the evaporator temperature, with no distinction from the evaporator process (d) To absolute zero, with no relation to the condenser pressure
80. "Superheating" of the refrigerant vapour leaving the evaporator refers to heating it:
    (a) Above its saturation temperature at that pressure (b) Below its saturation temperature at that pressure (c) To exactly the condenser temperature, with no distinction from the condenser process (d) To absolute zero, with no relation to the evaporator pressure

Section E: General Awareness, Computer Applications, and Current Affairs (20 Questions)

81. The National Institution for Transforming India (NITI Aayog) serves as India's premier:
    (a) Policy think tank, replacing the erstwhile Planning Commission (b) Judicial appellate body (c) Central bank, replacing the RBI (d) Railway zone headquarters
82. The Ministry of Skill Development and Entrepreneurship in India primarily focuses on:
    (a) Vocational training and entrepreneurship promotion (b) Railway signalling standards exclusively (c) Currency printing exclusively (d) Postal service standards exclusively
83. The full form of "IoT" in computing/engineering contexts is:
    (a) Internet of Things (b) Input Output Terminal (c) Integrated Optical Transmission (d) Internal Operations Team
84. In MS Word, the keyboard shortcut commonly used for "Save" is:
    (a) Ctrl+S (b) Ctrl+P (c) Ctrl+O (d) Ctrl+N
85. "Malware" is a general term referring to:
    (a) Malicious software designed to damage or disrupt systems (b) Authorised system utility software only (c) Hardware components only, with no software involved (d) A type of antivirus program exclusively
86. The Bureau of Energy Efficiency (BEE) in India administers energy conservation standards including:
    (a) Star rating labelling for appliances (b) Railway safety certification exclusively (c) Currency printing standards exclusively (d) Postal packaging standards exclusively
87. A "firewall" in computer networking is used to:
    (a) Monitor and control network traffic based on security rules (b) Physically cool the processor (c) Increase internet speed with no security function (d) Store user files permanently
88. Engineering research institutions like CSIR labs contribute primarily to:
    (a) Scientific research and technology development (b) Only railway ticketing operations (c) Only postal parcel sorting (d) Only currency exchange rate setting
89. Skill certification frameworks in India, such as the National Skills Qualification Framework (NSQF), aim to:
    (a) Standardise and align skill-based qualifications across sectors (b) Eliminate the need for any formal qualification (c) Apply only to government employees exclusively (d) Apply only to agricultural workers exclusively
90. The "Digital India" initiative's objectives include expanding:
    (a) Digital infrastructure and e-governance services (b) Only physical postal infrastructure, with no digital component (c) Only railway track infrastructure, with no digital component (d) Only currency printing infrastructure
91. The National Career Service (NCS) portal in India primarily assists with:
    (a) Employment exchange and career counselling services (b) Only railway ticket booking (c) Only postal address verification (d) Only currency exchange services
92. Industrial corridors being developed in India, such as the Delhi-Mumbai Industrial Corridor, aim to:
    (a) Boost industrial development and connectivity along the corridor (b) Eliminate all industrial activity along the corridor (c) Serve only as a tourist attraction with no industrial relevance (d) Apply only to the agricultural sector
93. E-Shram, a portal launched by the Government of India, is aimed at creating a database of:
    (a) Unorganised sector workers (b) Only government employees (c) Only foreign nationals working in India (d) Only railway employees exclusively
94. The term "additive manufacturing," synonymous with 3D printing, involves building parts by:
    (a) Adding material layer by layer (b) Removing material from a solid block (c) Melting and pouring into a mould exclusively (d) Forging under high pressure exclusively
95. Engineering standards bodies internationally, such as ISO, primarily aim to:
    (a) Establish standardised specifications for products, services, and systems (b) Eliminate the need for any standardisation (c) Apply only to one specific country, with no international scope (d) Apply only to food products, with no engineering relevance
96. The National Apprenticeship Certificate (NAC) is awarded upon successful completion of:
    (a) An approved apprenticeship training programme (b) A university postgraduate degree exclusively (c) A single-day orientation session only (d) A foreign exchange program only, unrelated to apprenticeship
97. "Vocal for Local," a phrase associated with India's self-reliance (Atmanirbhar Bharat) initiative, encourages:
    (a) Support for domestically manufactured goods (b) Exclusive reliance on imported goods (c) Discontinuation of all domestic manufacturing (d) Support only for the IT sector, with no manufacturing relevance
98. The Atmanirbhar Bharat Abhiyan (Self-Reliant India campaign) broadly aims at:
    (a) Promoting self-reliance across sectors, including manufacturing (b) Increasing dependence on imports exclusively (c) Applying only to the agricultural sector (d) Discouraging any domestic industrial growth
99. GeM (Government e-Marketplace) is a portal that facilitates:
    (a) Online procurement of goods and services by government departments (b) Only railway ticket booking for the general public (c) Only postal tracking services (d) Only currency exchange transactions
100. Engineering internships and industrial training, commonly undertaken during technical education, primarily aim to provide:
     (a) Practical, hands-on exposure to real industrial environments (b) Only theoretical classroom learning with no practical component (c) Only administrative office experience with no technical relevance (d) Only foreign travel experience, unrelated to engineering skills

Answer Key with Explanations

1.(a) A couple consists of two equal, parallel, opposite forces with non-coincident lines of action.

2.(a) A couple's moment is the same about any point.

3.(a) Equilibrium requires sum of forces = 0 and sum of moments about any point = 0.

4.(a) Angle of repose is where a body is on the verge of sliding.

5.(a) Radius of gyration relates moment of inertia to mass.

6.(a) D'Alembert's principle converts dynamics into equivalent statics via an inertia force.

7.(a) Impulse = force × time.

8.(a) Impulse-momentum principle: impulse = change in momentum.

9.(a) Poisson's ratio for metals is typically about 0.25–0.35.

10.(a) Combined direct and bending stress gives their algebraic sum at a point.

11.(a) Within the elastic limit, material returns to original shape.

12.(a) Ultimate tensile strength is the max stress on the engineering stress-strain curve.

13.(a) Necking is localized area reduction before fracture.

14.(a) A fixed beam has a lower maximum bending moment than a simply supported beam of same span/load.

15.(a) Shear force = algebraic sum of vertical forces on one side of a section.

16.(a) dM/dx = V relates bending moment and shear force.

17.(a) Parallel composite bars share equal strain, differing stress.

18.(a) Riveted joints are checked against tearing, shearing, and crushing.

19.(a) Bending stress varies linearly with distance from the neutral axis.

20.(a) Slenderness ratio determines buckling (long) vs. crushing (short) failure.

21.(a) A cyclic process returns the substance to its initial state.

22.(a) Specific volume = volume per unit mass.

23.(a) Enthalpy = internal energy + pV.

24.(a) SFEE for turbines often neglects PE changes relative to enthalpy/KE changes.

25.(a) Heat rejected = heat supplied − net work done (cyclic First Law).

26.(a) A refrigerator moves heat from cold to hot with external work input.

27.(a) Refrigerator COP = heat extracted / work input.

28.(a) Heat pump COP = heat delivered / work input.

29.(a) COP(HP) = COP(refrigerator) + 1.

30.(a) Otto cycle efficiency increases with compression ratio.

31.(a) Stirling cycle: two isothermal, two constant-volume processes.

32.(a) Brayton cycle: two isentropic, two constant-pressure processes.

33.(a) Combustion requires air (oxygen) with fuel in proper proportion.

34.(a) Excess air ensures more complete combustion.

35.(a) Calorific value is heat released per unit mass/volume upon combustion.

36.(a) HCV includes latent heat of water vapour formed; LCV excludes it.

37.(a) Cooling towers reject heat mainly via evaporative cooling.

38.(a) Load factor = average load / peak load.

39.(a) Base load plants run continuously at relatively constant high output.

40.(a) Peak load plants are designed for quick start-up during high demand.

41.(a) The single slider-crank chain underlies reciprocating IC engine mechanisms.

42.(a) Grashof's law: shortest + longest ≤ sum of the two intermediate links.

43.(a) A Scotch yoke converts rotary motion into SHM reciprocating motion.

44.(a) The addendum circle passes through tooth tips.

45.(a) The dedendum circle passes through tooth roots.

46.(a) The base circle generates the involute tooth profile.

47.(a) Contact ratio is the average number of tooth pairs in contact at once.

48.(a) A higher contact ratio gives smoother, quieter operation.

49.(a) Screw jack efficiency depends on helix angle and friction coefficient.

50.(a) A self-locking screw jack's load cannot descend once effort is removed.

51.(a) Machine efficiency = output work/power ÷ input work/power.

52.(a) Mechanical advantage = load / effort.

53.(a) Velocity ratio = distance moved by effort / distance moved by load.

54.(a) Gear train efficiency is reduced by friction at meshes and bearings.

55.(a) Coupling design must accommodate torque and shaft misalignment.

56.(a) Leaf spring flexibility depends on number, length, and thickness of leaves.

57.(a) The Wahl factor accounts for curvature and direct shear effects.

58.(a) A Hooke's joint gives non-uniform output speed for constant input speed.

59.(a) Flexible couplings suit shafts with some misalignment.

60.(a) Bearing life is highly sensitive to applied load (inverse power law).

61.(a) Continuity: area × velocity is constant for incompressible steady flow.

62.(a) A Pitot tube measures local flow velocity via stagnation/static pressure difference.

63.(a) An orifice meter measures flow rate via pressure drop across a constriction.

64.(a) A positive displacement pump traps and displaces a fixed fluid volume per cycle.

65.(a) Specific speed classifies/selects the appropriate turbine/pump type.

66.(a) Broaching removes material via a multi-tooth tool in a single linear pass.

67.(a) EDM removes material through controlled electrical sparks.

68.(a) Investment casting suits intricate, precise, fine-finish components.

69.(a) Die casting suits low-melting-point alloys like aluminium/zinc/magnesium.

70.(a) The "no go" end should not enter/pass if the component is within tolerance.

71.(a) Thermal conductivity expresses heat conduction ability (Fourier's law).

72.(a) Counter-flow generally gives higher effectiveness than parallel flow.

73.(a) The compressor raises refrigerant vapour pressure/temperature.

74.(a) Martensite is very hard but brittle.

75.(a) Case hardening suits components needing a hard surface with a tough core.

76.(a) FRP composites generally have less ductility/toughness and more complex manufacturing than metals.

77.(a) Boiler efficiency decreases with increasing flue gas heat losses.

78.(a) Slip gauges combine via wringing.

79.(a) Sub-cooling cools liquid refrigerant below its saturation temperature.

80.(a) Superheating heats vapour above its saturation temperature.

81.(a) NITI Aayog is India's policy think tank, replacing the Planning Commission.

82.(a) The Ministry of Skill Development focuses on vocational training/entrepreneurship.

83.(a) IoT stands for Internet of Things.

84.(a) Ctrl+S is the Save shortcut in MS Word.

85.(a) Malware is malicious software causing damage/disruption.

86.(a) BEE administers star rating labelling for appliances.

87.(a) A firewall monitors/controls network traffic per security rules.

88.(a) CSIR labs contribute to scientific research and technology development.

89.(a) NSQF standardises and aligns skill-based qualifications.

90.(a) Digital India expands digital infrastructure and e-governance.

91.(a) NCS assists with employment exchange and career counselling.

92.(a) Industrial corridors boost industrial development/connectivity.

93.(a) E-Shram creates a database of unorganised sector workers.

94.(a) Additive manufacturing (3D printing) adds material layer by layer.

95.(a) ISO establishes standardised specifications internationally.

96.(a) NAC is awarded on completing an approved apprenticeship programme.

97.(a) "Vocal for Local" encourages support for domestic goods.

98.(a) Atmanirbhar Bharat promotes self-reliance across sectors.

99.(a) GeM facilitates online government procurement.

100.(a) Engineering internships provide practical, hands-on industrial exposure.