The answer key has been derived from the official question paper (OMR-based) released through the iON DigiSolution platform. In this blog, we have compiled the complete answer key for both Section A (Technical – Mechanical Engineering) and Section B (General Aptitude, English, GK & Reasoning), along with subject-wise analysis, expected cutoff trends, and a step-by-step guide to raise objections.
| Detail | Information |
|---|---|
| Organisation | NCL (Coal India Limited) |
| Post | Asst. Foreman (Mechanical) Trainee |
| Grade | Grade C (T&S) |
| Exam Date | 26 April 2026 |
| Exam Time | 5:00 PM – 6:30 PM |
| Test Centre | iON Digital Zone iDZ2 Patliputra |
| Total Questions | 100 (Sec A: 70, Sec B: 30) |
| Exam Duration | 90 Minutes |
| Negative Marking | None |
| Parent Organisation | Coal India Limited (CIL) |
| Mode of Exam | Computer-Based Test (CBT) via iON Platform |
| Selection Process | Written Test → Document Verification → Medical |
| Job Location | Singrauli / NCL Command Area (MP & UP) |
| Official Website | nclcil.in |
Northern Coalfields Limited (NCL) is a Miniratna (Category-I) Public Sector Undertaking under the Ministry of Coal, Government of India. Headquartered in Singrauli, Madhya Pradesh, NCL operates multiple opencast coal mines across the Vindhyan coalfields region.
The Assistant Foreman (Mechanical) Trainee recruitment is part of NCL's ongoing effort to strengthen its technical workforce at the supervisory level. Candidates selected for this Grade C (T&S) post are placed on a structured training program before being regularised in the organization's mechanical maintenance wing.
The examination was divided into two sections. Section A tested domain knowledge in Mechanical Engineering, while Section B covered General Intelligence, English Language, General Awareness, and Numerical Ability.
| Section | Subject | Questions | Marks | Duration |
|---|---|---|---|---|
| Section A | Mechanical Engineering (Technical) | 70 | 70 | 90 Minutes (Combined) |
| Section B | Aptitude, English, GK, Reasoning | 30 | 30 | |
| Total | — | 100 | 100 | — |
The following table presents all 70 questions from Section A along with the correct answers as per the official question paper released for the 26 April 2026 shift.
| Q# | Question (Short) | Topic | Correct Answer |
|---|---|---|---|
| 1 | Physical quantity for twisting effect in a shaft | Theory of Machines | Torque |
| 2 | Correct expression for dryness fraction of steam | Thermodynamics | m_g / (m_f + m_g) |
| 3 | Term for energy associated with fluid motion (SFEE) | Thermodynamics | Kinetic Energy |
| 4 | Best cooling system for uniform engine temperature | IC Engines | Water Cooling (Controlled Circulation) |
| 5 | Coulomb friction in collar bearings occurs when | Engg. Mechanics | No Lubricating Fluid |
| 6 | Advantage of supercritical pressure in Benson Boiler | Steam Engineering | Increased Efficiency & Reduced Fuel Consumption |
| 7 | Primary use of a slab mill | Manufacturing | Producing Flat Surfaces |
| 8 | Relation between µ and ɸ (angle of friction) | Engg. Mechanics | µ = tan ɸ |
| 9 | Best cooling system during heavy engine load | IC Engines | Water Cooling System |
| 10 | NOT an assumption of Air Standard Cycle | Thermodynamics | Working fluid replaced after each cycle |
| 11 | Applied force when body is about to move = ? | Engg. Mechanics | Limiting Friction |
| 12 | Flow direction through impeller in axial flow pump | Fluid Mechanics | Axial Only |
| 13 | Stress twice as large as longitudinal in thin cylinder | Strength of Materials | Hoop Stress |
| 14 | Why antifreeze is added to coolant | IC Engines | To Raise Boiling Point of Coolant |
| 15 | Circumferential strain expression (σ₁, σ₂, E, µ) | Strength of Materials | (σ₁/E) − (µσ₂/E) |
| 16 | NOT an assumption in air-standard cycle | Thermodynamics | Heat supplied by chemical reactions |
| 17 | Element reducing turbulence initially in gating system | Manufacturing | Pouring Basin |
| 18 | Non-Newtonian fluid characterised by | Fluid Mechanics | Viscosity depends on shear rate |
| 19 | Clockwise cycle on P–V diagram indicates | Thermodynamics | Net work produced by system |
| 20 | Kelvin-Planck statement condition for heat engine | Thermodynamics | Some heat must be rejected to another reservoir |
| 21 | Newtonian fluid: shear stress vs shear rate | Fluid Mechanics | Linear |
| 22 | Coefficient of fluctuation of speed (N₁=210, N₂=190) | Theory of Machines | 0.10 |
| 23 | Boiler horsepower for 2,070 lb/hr steam production | Steam Engineering | 60 BHP |
| 24 | Ideal milling cutter for slots and pockets | Manufacturing | End Mill |
| 25 | Limiting friction is proportional to | Engg. Mechanics | Normal Reaction |
| 26 | Factor affecting mechanical efficiency at high speed | IC Engines | Increase in frictional power losses |
| 27 | Speed of gear D in compound gear train | Theory of Machines | 120 rpm |
| 28 | Discharge of radial pump (v=3 m/s, d=0.2 m) | Fluid Mechanics | 0.095 m³/s |
| 29 | Role of gating system in casting | Manufacturing | Controls flow of molten metal into mould |
| 30 | Fluid exhibiting shear-thinning behaviour | Fluid Mechanics | Pseudoplastic |
| 31 | B.M. variation in cantilever with load at free end | Strength of Materials | Linear increasing from free end to fixed end |
| 32 | Primary function of single plate clutch | Theory of Machines | Engage/Disengage engine power from transmission |
| 33 | Parameter NOT affecting polar moment of inertia | Strength of Materials | Length |
| 34 | Manometric efficiency (H_m=10, V_w2=10, u₂=20) | Fluid Mechanics | 0.50 |
| 35 | Helix angle in milling cutter primarily affects | Manufacturing | Max depth of cut without chatter |
| 36 | Primary purpose of riser in gating system | Manufacturing | Compensating shrinkage during solidification |
| 37 | Variation of frictional power with load | IC Engines | Remains nearly constant for varying loads |
| 38 | Horizontal line within saturation dome on T–S diagram | Thermodynamics | Constant temperature & pressure phase change |
| 39 | Does NOT influence equivalent evaporation | Steam Engineering | Boiler insulation thickness |
| 40 | NOT a form of energy in First Law for control volume | Thermodynamics | Entropy |
| 41 | Saturation curve on T–S diagram represents | Thermodynamics | Phase change boundary between liquid and vapour |
| 42 | Relation: Young's modulus E, Bulk modulus K, Shear modulus G | Strength of Materials | E = 9KG / (3K + G) |
| 43 | Pitch circle diameter (56 teeth, CP = 14 mm) | Theory of Machines | 249.45 mm |
| 44 | Significance of critical pressure in Benson Boiler | Steam Engineering | Prevents formation of steam bubbles in water |
| 45 | Power for centrifugal pump (Q=30 L/s, H=20 m, η=75%) | Fluid Mechanics | 8.0 kW |
| 46 | Angle of repose equals | Engg. Mechanics | Angle of friction (same surface condition) |
| 47 | Loeffler boiler is a _____ type | Steam Engineering | Water Tube |
| 48 | Superheated vapour region on T–S diagram lies | Thermodynamics | To the right of saturated vapour line |
| 49 | Constant P & T lines in wet steam region on T–S | Thermodynamics | Parallel to each other |
| 50 | Increase in working capacity without pressure increase | Steam Engineering | Only superheated steam |
| 51 | Compressed air application for underground mine safety | Mining Engineering | Ventilating mine tunnels |
| 52 | Tangent of angle of friction equals | Engg. Mechanics | Coefficient of Friction |
| 53 | Economizer improves steam plant efficiency by | Steam Engineering | Utilizing residual heat from flue gases |
| 54 | Fluid direction after entering impeller eye in radial pump | Fluid Mechanics | Flows radially outward from pump casing |
| 55 | Critical pressure of steam | Thermodynamics | 221 bar |
| 56 | Engine part causing maximum frictional losses | IC Engines | Piston rings and cylinder walls |
| 57 | How cone clutch transmits power | Theory of Machines | Frictional engagement of conical surfaces |
| 58 | B.M. at load point (SS beam, span L, load P at L/4) | Strength of Materials | 3PL/16 |
| 59 | Material for constructing superheaters in boilers | Steam Engineering | Stainless Steel |
| 60 | Intensity of pressure in fluid mechanics refers to | Fluid Mechanics | Pressure force per unit area on surface |
| 61 | Angle of friction φ is maximum when | Engg. Mechanics | µ = ∞ |
| 62 | Sequence for rigid vessel heated at constant volume | Thermodynamics | Compressed liquid → wet mixture → superheated vapour |
| 63 | Factor most directly reducing volumetric efficiency | IC Engines | High engine speed |
| 64 | Main advantage of superheated steam in turbine | Steam Engineering | Increased efficiency and power output |
| 65 | Reason for considering centrifugal tension in belt design | Theory of Machines | Prevent belt failure |
| 66 | Bulk modulus (Poisson's ratio=0.3, G=80 GPa) | Strength of Materials | 173.33 GPa |
| 67 | Condition for complete equilibrium of rigid body | Engg. Mechanics | ΣFx=0, ΣFy=0, ΣM=0 |
| 68 | NOT a requirement for defect-free casting gating design | Manufacturing | Gating system should be complex |
| 69 | NOT a type of milling cutter | Manufacturing | Flywheel |
| 70 | No-Slip Boundary Condition primarily affects which flow | Fluid Mechanics | Both Laminar and Turbulent flow |
| Q# | Question (Short) | Topic | Correct Answer |
|---|---|---|---|
| B.1 | Rearrange segments (Patriot Day) | English | DACB |
| B.2 | Vijay Merchant Trophy 2025 winner | GK (Sports) | Uttar Pradesh |
| B.3 | 5 men (12d) + 9 women (8d) together | Aptitude (Work) | 4.8 days |
| B.4 | Letters between symbols in series | Reasoning | Three |
| B.5 | Young, weak, flexible mountain range in India | GK (Geography) | Himalayas |
| B.6 | Speed to cover remaining 24 km in 2 hrs | Aptitude (Speed) | 12 km/h |
| B.7 | Year UN Declaration signed (India signatory) | GK (History) | 1942 |
| B.8 | Odd pair out (VU-SK, KJ-HG, PO-ML, TS-QP) | Reasoning | VU – SK |
| B.9 | Cost price when sold at ₹308, 12% gain | Aptitude (P&L) | ₹275 |
| B.10 | City of inaugural Kho Kho World Cup (Jan 2025) | GK (Sports) | New Delhi |
| B.11 | Synonym of 'disparage' | English | Belittle |
| B.12 | Successive discounts 15% and 16% = single | Aptitude | 28.6% |
| B.13 | Light & dark bands at shadow boundary | Science (Physics) | Diffraction |
| B.14 | Common letters in PROTEIN transformation | Reasoning | Two |
| B.15 | Banks nationalised in 1969 (first phase) | GK (Economy) | Fourteen |
| B.16 | Award for retired sportspersons promoting sports | GK (Awards) | Arjuna Award (Lifetime) |
| B.17 | Simran's profit (Raj ₹10k/8mo, Simran ₹15k/12mo) | Aptitude | ₹9,000 |
| B.18 | Proverb for "efforts don't guarantee success" | English | You can't win them all |
| B.19 | "Vision of a Free India" speech, Poona 1928 | GK (History) | Subhas Chandra Bose |
| B.20 | Gain % (marked 48% above CP, 10% discount) | Aptitude | 33.2% |
| B.21 | One word: person believing in no government | English | Anarchist |
| B.22 | Speed of first train (66m overtaking 88m) | Aptitude (Trains) | 85 km/h |
| B.23 | Mass constant in chemical/physical change | Science (Chemistry) | Law of Conservation of Mass |
| B.24 | People between C and U in seating (7 people) | Reasoning | Two |
| B.25 | Pravin alone paints hall (together 7d, Nitin 56d) | Aptitude (Work) | 8 days |
| B.26 | CP of article (listed ₹5000, 20% disc, 25% profit) | Aptitude | ₹3,200 |
| B.27 | W related to Y in coded family relation | Reasoning | Wife's father's sister |
| B.28 | "Bread and butter ___ my favourite…" | English (Grammar) | is |
| B.29 | Article for freedom of speech in Indian Constitution | GK (Polity) | Article 19 |
| B.30 | Time for trains to cross (150m@72 + 250m@54, opposite) | Aptitude (Trains) | 11.43 seconds |
| Topic | Questions | Accuracy |
|---|---|---|
| Thermodynamics | 18 | ~89% |
| Fluid Mechanics & Machines | 14 | ~79% |
| Strength of Materials | 10 | ~80% |
| Theory of Machines | 9 | ~89% |
| Steam Engineering & Boilers | 11 | ~82% |
| IC Engines | 8 | ~75% |
| Manufacturing & Casting | 7 | ~86% |
| Engineering Mechanics | 7 | 100% |
| Category | Expected Cutoff (out of 100) |
|---|---|
| General (UR) | 62 – 70 |
| OBC (NCL) | 56 – 64 |
| SC | 48 – 56 |
| ST | 44 – 52 |
| EWS | 58 – 66 |
| PwBD | 40 – 48 |
| Stage | Description | Timeline |
|---|---|---|
| 1. Answer Key Release | Preliminary answer key published | Apr–May 2026 |
| 2. Objection Window | Candidates raise challenges | ~5–7 days after |
| 3. Final Answer Key | Revised key after expert review | May–Jun 2026 |
| 4. Result Declaration | Merit list based on cutoff | Jun–Jul 2026 |
| 5. Document Verification | Shortlisted candidates called | Jul–Aug 2026 |
| 6. Medical & Appointment | Physical fitness + offer letter | Aug–Sep 2026 |
Bookmark this page and check nclcil.in regularly for the official result, final answer key, and merit list.
Visit NCL Official Website ↗The NCL 2026 Assistant Foreman (Mechanical) Trainee exam was a well-balanced paper of moderate difficulty. Thermodynamics, Fluid Mechanics, and Steam Engineering formed the backbone of Section A. Section B was straightforward for candidates with solid preparation in Maths, Reasoning, and current affairs.
Candidates who scored 65+ have a strong chance of making the merit list for General category. If you identify discrepancies in the answer key, raise a formal objection through the official portal with supporting documentation. We wish all candidates the very best! ????️
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