RRB JE PYQs 22 April 2025 (2:30 PM – 4:30 PM)
1. Which of the following materials is likely to have the highest thermal conductivity?
1. Rubber
2. Air
3. Aluminium
4. Wood
Answer: 3
2. Which characteristics best describes an axial flow pump?
1. The fluid flows parallel to the pump shaft .
2. The fluid flows radially outward from the shaft .
3. The fluid flows perpendicular to the pump shaft .
4. The fluid flow is converted to heat energy .
Answer: 1
3. Which of the following are used to improve pigment dispersion and the stability of coating during organic coating?
1. Colloidal stabilisers
2. Pigment analyser
3. Curing stabilisers
4. Plasticisers
Answer: 1
4. What is the primary function of the tool post in a lathe machine?
1. To secure the workpiece firmly on the machine bad
2. To control the feed rate and depth of cut during machining
3. To hold and adjust the tool for a suitable working position
4. To support the compound rest and provide rotational movement
Answer: 3
5. The S-N curve in fatigue testing shows the relationship between :
1. The number of cycles and strain amplitude
2. The number of cycles and stress amplitude
3. Stress and strain
4. Stress and displacement
Answer: 2
6. Slag inclusion is the welding defect caused by ______ .
1. Gas being trapped , due to moisture
2. Insufficient cleaning and preparation of the base metal before welding commences
3. Contamination of either the filler or parent metals
4. Incorrect edge penetration
Answer: 2
7. Tungsten Inert Gas Welding (TIG) is also called ______ .
1. Metal Inert Gas Welding
2. Gas Tungsten Arc Welding
3. Gas Metal Arc Welding
4. Thermo-compression Welding
ย Answer: 2
8. Which of the following centre-less grinding can be preferred for headed , stepped , or taper shaped workpiece?
1. Plunge cut grinding
2. Taper out grinding
3. Rotational feed center less grinding
4. Out feed grinding
Answer: 1
9. Which statement best compares battery and magneto ignition systems in internal combustion engines?
1. Magneto systems require more frequent maintenance than battery systems .
2. Battery ignition systems are independent of engine speed , unlike magneto systems .
3. Battery ignition systems rely on stored electrical energy , whereas magneto systems generate power on demand via electromagnetic induction .
4. Both systems depend on an external battery for operation .
Answer: 3
10. In brazing , the filler metal is drawn into the joint by means of ____ .
1. Friction
2. Damping action
3. Capillary action
4. Surface tension
Answer: 3
11. In Arc Welding Processes , GMAW stands for _______ .
1. Gas Metal Arc Welding
2. Gas Molten Arbour Welding
3. Gas Molten Arc Welding
4. Gang Metal Arc Welding
Answer: 1
12. Which type of light is generally used in the photo etching process ?
1. Infrared (IR) light
2. X-ray
3. Visible light
4. Ultravoilet (UV) light
Answer: 4
13. How is the resultant forces calculated if two forces act along the same straight line but in opposite directions ?
1. R = F1 + F2
2. R = โF1ยฒ + F2ยฒ
3. R = 2F1F2 cosฮธ
4. R = F1 – F2
Answer: 4
14. The radius of gyration about the polar axis of a circular lamina of radius 0.2 m is :
1. 4.1 cm
2. 0.14 m
3. 0.1 m
4. โ cm
Answer: 2
15. The intake valve closes at _____ for a low speed engine and at ____ for high speed four stroke petrol engines .
1. 60 deg after BDC ; 10 deg after BDC
2. 10 deg before BDC ; 60 deg after BDC
3. 60 deg before BDC ; 10 deg before BDC
4. 10 deg after BDC ; 60 deg after BDC
Answer: 4
16. If the external diameter of a hollow shaft is three times greater than its internal diameter , what is the ratio of its torque – carrying capacity compared to that of a solid shaft of identical material and the same outer diameter ?
1. 65/81
2. 80/81
3. 26/27
4. 81/80
Answer: 2
17. In which type of engine is a mist lubricating system most commonly used ?
1. Gas turbine engines
2. Rotary engines
3. Four – stroke diesel engine
4. Two – stroke petrol engine
Answer: 4
18. Which of the following is a common metrological application of interferometry?
1. Determining surface hardness
2. Analysing chemical composition
3. Measuring temperature
4. Inspecting machine parts for straightness
Answer: 4
19. What does specific fuel consumption (SFC) measure in an internal combustion engine?
1. The efficiency of the engine’s exhaust system
2. The total mass of the fuel used during engine operation
3. The fuel efficiency expressed as the amount of fuel consumed per unit of power produced
4. The ratio of air intake to fuel delivered per combustion cycle
Answer: 3
20. The Zeroth Law of Thermodynamics established the basis for which of the following?
1. Entropy increase in isolated systems
2. Heat transfer through conduction
3. Conservation of energy
4. Measurement of temperature
Answer: 4
21. A pump discharges water with a manometric head of 20 m . If the density of water is 1000 kg/mยณ and gravity is 9.81 m/sยฒ , what is the approximate pressure increase provided by the pump?
1. 20 kPa
2. 2 kPa
3. 196 kPa
4. 9.81 kPa
Answer: 3
22. Broaching of outside surfaces is called ____ .
1. Internal broaching
2. Hallow broaching
3. Surface broaching
4. Hole broaching
Answer: 3
23. How many mirrors are used for magnification in the Zeiss Ultra Optimeter?
1. One
2. Two
3. Three
4. Four
Answer: 2
24. In most of the SI engines , the intake valve opens a few degrees before the TDC on the exhaust stroke to :
1. Allow for better scavenging of exhaust gases
2. Ensure that the intake valve is fully open when the piston reaches the TDC .
3. Ensure complete combustion of the fuel – air misture
4. Increase the engine’s compression ratio
Answer: 1
25. Which of the following is not a function of the spirit level measuring instrument?
1. For measuring surface roughness
2. For determining flatness and straightness
3. For measuring angles
4. For measuring alignment of machine parts
Answer: 1
26. Electroplating is the opposite of which of the following?
1. Electrolysis
2. Battery charging
3. Galvanic cell
4. Fuel cell
Answer: 3
27. The primary purpose of job rating or evaluation is to:
1. Provide benefits like leave and housing
2. Assess an employee’s performance
3. Motivate employees for higher production
4. Determine the relative worth of different jobs
Answer: 4
28. What is the primary function of the tailstock in a lathe?
1. To change the direction of the spindle movement
2. To provide support and bearing for the rotating job
3. To hold the cutting tool for machining operations
4. To control the speed of the spindle rotation
Answer: 2
29. A pilot tube is primarily used to measure:
1. Dynamic pressure
2. Static pressure
3. Atmospheric pressure
4. Flow velocity
Answer: 4
30. In rack and pinion gear , the rack is a _____ and the pinion is a ______ .
1. Straight line gear ; straight line gear
2. Straight line gear ; circular wheel
3. Circular wheel ; straight line gear
4. Circular wheel ; circular wheel
Answer: 2
31. Which of the following is a special case of spirit level device?
1. Micrometer
2. Clinometer
3. Autocollimator
4. Kelvinometer
Answer: 2
32. Angle gauges are generally made from which material?
1. Carbon fibre
2. Hardened steel
3. Woodย
4. Plastic
Answer: 2
33. In which type of oxy-acetylene welding flames are both acetylene and oxygen in equal proportions?
1. Neutral welding flame
2. Oxidising welding flame
3. Reducing welding flame
4. Carburising welding flame
Answer: 1
34. Which of the following types of steel would not typically undergo the normalising process?
1. High carbon steel
2. Alloy steel
3. Medium carbon steel
4. Stainless steel
Answer: 4
35. Which of the following beams is classified as a statically determinate beam?
1. Propped cantilever beam
2. Continuous beam
3. Overhanging beam
4. Fixed beam
Answer: 3
36. A gray body is defined as a body that :
1. Absorbs all radiation incident upon its surface
2. Reflects all radiation incident upon its surface
3. Has emissivity less than 1 but constant for all wavelengths
4. Has an emissivity that varies with wavelength of radiation
Answer: 3
37. Fluid pressure is defined as :
1. The force per unit area exerted by a fluid at rest
2. Reflects all radiation incident upon its surface
3. Has emissivity less than 1 but constant for all weights
4. The rate of the flow of fluid through a given area
Answer: 1
38. What is the function of coolants in metal cutting or machining operation?
1. Decrease adhesion between the chip and tool
2. Provides higher friction and wear between tool and workpiece
3. Increases wear and tear of tools and decrease tool life
4. Reduces machinability and machining forces
Answer: 1
39. If elastic strength increases 3 time , then Proof Resilience :
1. Increases 3 times
2. Decreases 9 times
3. Decreases 3 times
4. Increases 9 times
Answer: 4
40. In a two stroke petrol engine , the primary function of the crankcase is to:
1. House the transfer port
2. Store lubricating oil
3. Cool the engine
4. Act as a primary pumping chamber for the fuel mixture
Answer: 4
41. If a component has a Factor of Safety (FoS) of 1.0 , What does it indicate?
1. The design is highly conservative .
2. The component will never fall irrespective of any load
3. The design is unsafe and should not be designed
4. The material will fail exactly at the expected load .
Answer: 4
42. What will be the shape of the bending moment diagram for a cantilever beam carrying a uniformly distributed load throughout its length?
1. Cubical
2. Straight line
3. A parabola
4. A Hyperbola
Answer: 3
43. The primary reason for diesel engines having more efficiency than gasoline engines is they ____ .
1. Have a longer stroke
2. Have a higher compression ratio
3. Use a different fuel
4. Operate at higher temperature
Answer: 2
44. Which type of fracture is most likely to occur in a material with high tensile strength but low ductility?
1. Fatigue failure
2. Ductile fracture
3. Creep failure
4. Brittle fracture
Answer: 4
45. In the _____ welding technique , the welding rod is applied before the welding torch in the direction of motion .
1. Forehand
2. Backhand
3. Laser
4. Electric arc
Answer: 1
46. In climb milling , metal is removed by the cutter rotating in the ____ .
1. Opposite direction of the feed of the workpiece
2. Perpendicular direction of the feed of the workpiece
3. Same direction of the feed of the workpiece
4. Diagonal direction of the feed of the workpiece
Answer: 3
47. Which of the following is an operational function that comes under pre-planning ?
1. Dispatching
2. Material planning and control
3. Loading
4. Forcasting
Answer: 4
48. Which of the following elements provides the necessary horizontal force to the workpiece in centerless grinding?
1. Regulating wheel
2. Stationary wheel
3. Work test blade
4. Revolving wheel
Answer: 1
49. In the CPM technique , the critical path slack is :
1. Zero
2. Negative
3. Either negative or zero
4. Positive
Answer: 1
50. If the temperature of a black body doubles , how many times will its emissive power increase ?
1. 8 times
2. 4 times
3. 16 times
4. 2 times
Answer: 3
51. Frictional power in an engine is calculated as :
1. Indicated power – Brake power
2. Brake power / Mechanical efficiency
3. Indicated power + Brake power
4. Indicated power x Mechanical efficiency
Answer: 1
52. In carburising welding flame , there is a supply of _____ in the combustible mixture .
1. Limited acetylene proportion and more oxygen proportion .
2. Acetylene and oxygen in equal proportion
3. More acetylene proportion and limited oxygen proportion
4. Only oxygen
Answer: 3
53. ______ type of electrode is used in Gas Tungsten Arc Welding (GTAW) .
1. Non – consumable tungsten
2. Consumable bare
3. Consumable coated
4. Non – consumable carbon
Answer: 1
54. Which alloying element in alloy steel is primarily responsible for enhancing corrosion resistance?
1. Chromium
2. Magnesium
3. Silicon
4. Carbon
Answer: 1
55. The type of lasers commonly used in laser interferometers for metrology applications are ______ .
1. Solid – state lasers
2. Dye lasers
3. Gas lasers
4. Excimer lasers
Answer: 3
56. In Carbon Arc Welding , DCSP stands for ______ .
1. Direct current straight porosity
2. Direct current Straight pressure
3. Direct current straight polarity
4. Dual current straight polarity
Answer: 3
57. In Arc welding process , chipping hammer is used to ______ .
1. Clean the surface to be welded .
2. Remove the slag by striking .
3. Protect the eyes .
4. Hold the electrode manually and conducting current to it .
Answer: 2
58. How does atmospheric pressure influence gauge pressure measurements ?
1. Gauge pressure is independent of atmospheric pressure .
2. Gauge pressure equals atmospheric pressure minus absolute pressure .
3. Gauge pressure is the difference between absolute pressure and atmospheric pressure .
4. Gauge pressure is the sum of absolute and atmospheric pressure .
Answer: 3
59. What is the full form of ‘CBN’ , which is used as an abrasive in grinding processes?
1. Calcium bi nitrous
2. Carbon boron nitrate
3. Copper boron nitrate
4. Cubic boron nitride
Answer: 4
60. Drill chuck is the major part of drilling machines , which _____ .
1. Transmits rotary motion to the drill spindle at a number of speeds
2. Rests on the base and supports the head and the table
3. Holds the drill bit
4. Holds electric motor , V-pulleys and V-belt
Answer: 3
61. While measuring surface texture , the part of the profilometer that makes contact the workpiece surface is:
1. An electrical pickup
2. A finely pointed stylus
3. A motorised mechanism
4. A recording unit
Answer: 2
62. What is a characteristics of a coplanar parallel force system?
1. Forces act in different planes and are parallel
2. Forces act in the same plane but are not paralll .
3. Forces act in different planes and are not parallel
4. Forces act in the same plane and are paralle
Answer: 4
63. Which of the following factors generally increases the brittleness of a material?
1. High alloy content
2. Low temperature
3. High temperature
4. High strain rate
Answer: 2
64. A simply supported beam with a span length of 5m carries a moment of 20 N-m (counterclockwise direction) at the middle of the beam . What will the value of reactions be at both the ends of the beam?
1. 4 N , -4 N
2. 8 N , -8 N
3. 5 N , -5 N
4. 2 N , -2 N
Answer: 1
65. Why does stainless steel resist rusting , while regular carbon steel does not?
1. Stainless steel has a thicker iron content
2. Stainless steel has a protective chromium oxide layer that prevents rusting
3. Stainless steel has higher carbon content which makes if corrosion resistant .
4. Stainless steel is coated with a special anti-rust chemical .
Answer: 2
66. A beam with a symmetrical T section has a top flange 50 mm wide and 20 mm thick , and a web 40 mm high and 10 mm thick . An additional plate , 10 mm thick and 60 mm wide is welded above the flange . The moment of inertia of this symmetrical planar cross-section about an axis in its plane normal to the web and in line with the upper face of the 10 mm thick plate works out to 1506,666.66 mm^4 . The centroidal axis of the combines area is 21.5 mm below this axis , normal to the web . The moment of inertia of this built-up area about the centroidal axis is (in mm^4) :
1. 2,17,833.34
2. 70,077.52
3. 5,82,166.66
4. 1.33 x 10^5
Answer: 3
67. In which of the following situations would brittleness be most UNDESIRABLE?
1. In materials used in high-speed applications
2. In tools that need to withstand heavy impact
3. In structural beams under static load
4. In materials exposed to high temperatures
Answer: 2
68. When two equal forces F act at an angle ฮธ , the resultant force is given by which of the following expressions?
1. R = 2Fsin(ฮธ/2)
2. R = F1 + F2
3. R = F1 – F2
4. R = 2Fcos(ฮธ/2)
Answer: 4
69. A symmetrical I-section has a moment of inertia about the centroidal axis in its place perpendicular to the web , of 22.34 x 10^4mm^4 . The moment of inertia of the full rectangular area occupied by the I-beam cross section about the axis is 65 x 10^4 mm^4 . The two empty spaces on ither side of the web are square . What is the height of the web?
1. 50 mm
2. 30 mm
3. 55 mm
4. 40 mm
Answer: 4
70. _____ is a welding defect caused by trapping of gas during the welding process .
1. Undercut
2. Burn through
3. Cracking
4. Porosity
Answer: 4
71. Which of the following is a benefit of using Material Requirements Planning (MRP)?
1. Reduced customer
2. Increased raw material costs
3. Better inventory planning and schedule
4. Slower response to market change
Answer: 3
72.ย According to Maslow’s Hierarchy of Needs , the basic requirements of the human body such as food , water , sleep , etc. are categorised into:
1. Physiological needs
2. Esteem needs
3. Self – actualisation needs
4. Social needs
Answer: 1
73. Compared to axial flow pumps , radial flow pumps typically :
1. Generate higher pressures with lower flow rates
2. Are used exclusively for pumping gases
3. Have lower efficiency in all applications
4. Produce higher flow rates at lower pressures
Answer: 1
74. An engine is assumed to be working on ideal Otto cycle with the temperatures at the beginning and end of compression as 27ยฐC and 327ยฐ C . The air – standard efficiency of the engine is :
1. 87%
2. 78%
3. 60%
4. 50%
Answer: 4
75. Manometric head is defined as :
1. The height of a fluid column corresponding to the pump’s output pressure
2. The weight of the pump
3. The temperature difference across the pump
4. The fluid velocity within the pump
Answer: 1
76. Which of the following material has the highest compressive strength?
1. Copperย
2. Mild steel
3. Rubber
4. Cast iron
Answer: 4
77. Which of the following represents the polar modulus of the hollow shaft?
[If Do = External diameter and Di = Internal diameter]
1. [16ฮ /Do] [Do4 – Di4]
2. [ฮ /16Do] [Do3 – Di3]
3. [ฮ /16Do] [Do4 – Di4]
4. [16/ฮ Do] [Do4 – Di4]
Answer: 3
78. While scheduling decisions , the most influencing parameter is :
1. Market research
2. Sales forecasting
3. Competitor pricing
4. Availability of skilled personnel
Answer: 2
79. In an ideal four – stroke engine , the assumption made about the burning process during the power stroke i.e., after compression is :
1. It occurs instantaneously when the piston is at the top dead centre .
2. It starts at the bottom dead centre and continues as the piston moves up .
3. It is a gradual process that starts before the piston reaches top dead centre .
4. It takes a significant amount of time .
Answer: 1
80. In the Charpy impact test , the specimen is typically :
1. A cylindrical rod with no defects
2. A rectangular bar with a notch in the middle
3. A sheet of material placed under compression
4. Subjected to a gradual tensile load
Answer: 2
81. A steel bar (E = 200E = 200 , ฮฑ = 12 x 10 – 6/ยฐC) expands by 0.3 mm due to a temperature increase . If the original length of the bar was 15 cm , what was the temperature rise?
1. 166.6ยฐC
2. 100ยฐC
3. 180ยฐC
4. 120.6ยฐC
Answer: 1
82. What is the capability of a profilometer instrument ?
1. Measure surface waviness only
2. Measure surface roughness only
3. Measure surface flaws only
4. Measure roughness together with waviness and any other surface flaws
Answer: 4
83. What will be the nature of longitudinal stress in a thin closed cylinder containing hydrostatic fluid pressure ?
1. Bending
2. Shear
3. Compressive
4. Tensile
Answer: 4
84. Which of the following happens when two equal and opposite forces are applied at a point on a rigid body?
1. They produce an additional force on the body
2. They create rotational motion in the body
3. They cancel each other and have no effect
4. They change the magnitude of the original force
Answer: 3
85. One challenge associated with double volute casing is:
1. Increased complexity in manufacturing and alignment
2. Higher risk of leakage due to multiple seams
3. Decreased efficiency in converting kinetic to pressure energy
4. Reduced flow rates
Answer: 1
86. To machine an internal hole in a broaching operation , the broach is grippled by the _____ .
1. Puller at the pilot
2. Puller at the face of the teeth
3. Puller at the flute
4. Puller at the shank end
Answer: 1
87. Which of the following is the surface coating process?
1. Tumbling
2. Hot doping
3. Hot dipping
4. Pickling
Answer: 3
88. Which of the following is a limitation of taper turning by swiveling the compound rest?
1. It ensures the best surface finish .
2. It is suitable only for short tapers .
3. It provides high production efficiency .
4. It cannot turn any type of taper
Answer: 2
89. What is the designated function of a ‘planetary internal grinding machine’?
1. For a work piece of irregular shape
2. For a very small work piece
3. For a work piece of regular shape
4. For a low precision surface finish
Answer: 1
90. Which of the following processes produces the minimum surface roughness on workpiece ?
1. Honing
2. Superfinishing
3. Grinding
4. Lapping
Answer: 2
91. How does the volute shape in a single volute pump casing affect performance?
1. It helps maintain a uniform flow distribution .
2. It increases turbulence within the pump .
3. It restricts the pump’s operating range
4. It serves only an aesthetic purpose
Answer: 1
92. The factor considered for wage determination in the flat day rate basic wage incentive plan is:
1. Individual performance
2. Number of pieces produced
3. Company profit
4. Hours worked
Answer: 4
93. Which of the following is an operational function that comes under pre-planning?
1. Dispatching
2. Material planning and control
3. Loading
4. Forecasting
Answer: 4
94. The master production schedule represents the :
1. Starting time of component manufacturing
2. Financial requirements for the production
3. Starting and finishing time of different products
4. Finishing time of component manufacturing
Answer: 3
95. Priming of a pump refers to :
1. Removing air from the pump casing and suction line
2. Lubricating the pump bearings
3. Increasing the rotational speed of the pump
4. Adjusting the impeller clearance
Answer: 1
96. The primary purpose of a shadow projector is to _____ .
1. Detect internal flaws in a material
2. Analyse material composition
3. Produce an undistorted magnified reflected image of an object
4. Measure surface roughness
Answer: 3
97. The Bell-Coleman cycle is also known as:
1. Reversed Brayton cycle
2. Brayton cycle
3. Rankine cycle
4. Carnot cycle
Answer: 1
98. For a symmetrical T-section , the moment of inertia through centroidal axes in its place parallel to the flange Ixx = 2 x 10^7 mm^4 , and perpendicular to the flange is Iyy = 1.5 x 10^7 mm^4 . The moment of inertia about the centroidal axis normal to the planar area works out to (in mm^4) :
1. 1.33 x 10^7
2. 2.5 x 10^7
3. 3.5 x 10^7
4. 0.5 x 10^7
Answer: 3
99. Which of the following best defines vapour pressure in a liquid?
1. The pressure exerted by the vapour in equilibrium with its liquid at a given temperature
2. The pressure exerted by the liquid molecules
3. The pressure required to force the liquid into a capillary tube
4. The difference between atmospheric pressure and absolute pressure
Answer: 1
100. Which of the following options best describes non-coplanar concurrent forces?
1. Forces that meet at one point but their lines of action do not lie on the same plane .
2. Forces that do not meet at one point and their lines of action lie on the same plane .
3. Forces that meet at one point and their lines of action lie on the same plane .
4. Forces that do not meet at one point but their lines of action lie on different planes .
Answer: 1
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