RRB ALP 2025 CBT 2 Mechanic Diesel Previous Year Question Paper and Answer Key Free PDF Download English
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CBT Stage-2 | Mechanic Diesel Trade | Question Paper with Answer Key
Test Date: 28/07/2026 | Test Time: 9:30 AM – 12:00 PM | Shift-1
Note: Correct Answer = 1 mark | Incorrect = −1/3 mark. Bold ✓ indicates official correct option.
PART-A (Common Section)
Questions 1 – 100 (Detailed selection + Key)
Q.1 Two students move identical boxes through a distance of 10 m. Student A applies a force of 50 N, while Student B applies a force of 100 N. What is the difference in the work done by the two students?
A. 0 J
B. 50 J
C. 500 J ✓
D. 1000 J
Correct Answer: C
Q.2 Based on the English alphabetical order, three of the following four letter-cluster pairs are alike in a certain way and thus form a group. Which letter-cluster pair DOES NOT belong to that group?
A. QK-VA ✓
B. EY-KO
C. WQ-CG
D. TN-ZD
Correct Answer: A
Q.3 Namia is facing the west. She turns left and walks 15 m. She turns left and walks 25 m. She again turns left and walks 40 m. She finally turns left and walks 40 m to reach home. In which direction is her home with respect to the starting point?
A. South-West
B. South-East
C. North-West ✓
D. North-East
Correct Answer: C
Q.4 A car travels 60 km north in 2 hours, then 40 km south in the next 1 hour. What is the car's average velocity over the entire trip?
A. 20 km/h south
B. 6.7 km/h north ✓
C. 0 km/h
D. 33.3 km/h north
Correct Answer: B
Q.5 A father distributed two different amounts among his sons P, Q, R and S. First amount was distributed in the ratio 5 : 4 : 3 : 2 and the second amount was distributed in the ratio 6 : 7 : 8 : 9. If the second amount is thrice the first amount, then which son will get the maximum amount?
A. Q
B. P
C. R
D. S ✓
Correct Answer: D
Q.6 Three pipes A, B and C can fill a tank in 12 hours, 18 hours and 24 hours, respectively. A leak at the bottom can empty the full tank in 36 hours. If all the pipes are opened together, in how many hours will the tank be filled? (Round off your answer to two decimal places.)
A. 5.56 hours
B. 9.45 hours
C. 3.33 hours
D. 6.55 hours ✓
Correct Answer: D
Q.7 A conical tent has a base radius of 14 m and a height of 48 m. How many cubic meters of air can it hold? (Use π = 22/7)
A. 8956
B. 9568
C. 9865
D. 9856 ✓
Correct Answer: D
Q.8 What is the simplified value of the expression [cos A / (1 − tan A)] + [sin A / (1 − cot A)]?
A. 0
B. sin A − cos A
C. cos A + sin A ✓
D. 1
Correct Answer: C
Q.9 If (x + 1/x) = 3, find the value of (x³ + 1/x³).
A. 15
B. 16
C. 18 ✓
D. 20
Correct Answer: C
Q.10 If a scooter travels at a constant speed of 25 km per hour, how far will it travel in 4 hours?
A. 75 km
B. 120 km
C. 100 km ✓
D. 80 km
Correct Answer: C
Q.11 Three workers, X, Y, and Z, can complete a certain job in 10 days, 12 days, and 15 days, respectively. Determine the number of days required for them to complete the job when they work together.
A. 8 days
B. 6 days
C. 4 days ✓
D. 5 days
Correct Answer: C
Q.12 There are two types of silver-copper alloys... Find the amount of the first alloy that should be mixed... to obtain a 100 kg mixture containing 90% silver.
A. 52 kg
B. 45 kg
C. 48 kg
D. 50 kg ✓
Correct Answer: D
Q.13 A roller coaster at the top of its track has maximum potential energy. As it descends and speeds up, what principle explains why the sum of its kinetic and potential energies remains constant if we ignore friction and air resistance?
A. Principle of inertia
B. Principle of superposition
C. Law of inertia
D. Law of conservation of energy ✓
Correct Answer: D
Q.14 Select the pair which follows the same pattern as that followed by the two pairs given below. BIP : EMU GNU : JRZ
A. CGW : NHT
B. XDE : PON
C. FMT : IQY ✓
D. VCD : GRD
Correct Answer: C
Q.15 If Rohan's income increases by 20% and his expenditure increases by 10%, then his savings increase by ₹1,200. If his original income was ₹12,000, what was his original expenditure?
A. ₹9,000
B. ₹11,000
C. ₹12,000 ✓
D. ₹10,000
Correct Answer: C
Q.16 Which of the following statements correctly describes average velocity and its SI unit?
A. Average velocity is the total displacement divided by total time, and its unit is kilometer per hour.
B. Average velocity is the total distance divided by total time, and its unit is meter per second.
C. Average velocity is the total distance divided by total time, and its unit is kilometer per hour.
D. Average velocity is the total displacement divided by total time, and its unit is meter per second. ✓
Correct Answer: D
Q.17 A pendulum takes 60 seconds to complete 24 oscillations. If its length is increased and it now takes 72 seconds for the same number of oscillations, what has happened to its time period?
A. It has increased to 3.0 seconds ✓
B. It has decreased to 2.0 seconds
C. It has decreased to 1.5 seconds
D. It remains at 2.5 seconds
Correct Answer: A
Q.18 When a moving car suddenly applies brakes, its kinetic energy is transformed mainly into which form of energy?
A. Heat energy ✓
B. Light energy
C. Sound energy
D. Potential energy
Correct Answer: A
Quick Answer Key – Remaining Part-A
Remaining Part-A questions follow the official answer key pattern (common section). Full options available in the original PDF.
PART-B (Mechanic Diesel Trade Specific)
Diesel engines, Emission control, Turbocharger, Camshaft, Measuring instruments etc.
Q.1 What is a direct mechanical reason for low power generation in a diesel engine?
A. Damaged fan belt
B. Faulty alternator
C. Worn piston rings ✓
D. Incorrect coolant level
Correct Answer: C
Q.2 Which component works directly with engine valves to manage air and exhaust flow in a diesel engine?
A. The crankshaft
B. The fuel injector
C. The flywheel
D. The camshaft ✓
Correct Answer: D
Q.3 In the context of diesel engines, which of the following best describes the primary objective of emission standards?
A. Increase smoke emission
B. Reduce engine power
C. Increase fuel wastage
D. Reduce pollution levels ✓
Correct Answer: D
Q.4 Which component is commonly used in evaporative emission control systems to store fuel vapors temporarily?
A. Air filter case housing
B. Activated charcoal canister ✓
C. Radiator expansion tank
D. Oil separator ball valve
Correct Answer: B
Q.5 A technician observes that after a diesel engine runs for several hours, the vehicle’s exhaust sound becomes much louder and a strong smell is detected at the tail pipe. What is the most probable function of the muffler being compromised in this situation?
A. To convert exhaust gases and neutralize pollutants
B. To redirect exhaust gases and control flow only
C. To silence exhaust noise and cool gases before exit ✓
D. To regulate exhaust back pressure for engine braking
Correct Answer: C
Q.6 Which part of the Vernier caliper slides along the main scale for measurement?
A. Lower jaw
B. Lock screw
C. Depth rod
D. Vernier scale ✓
Correct Answer: D
Q.7 During maintenance, a supervisor asks the role of a turbocharger when atmospheric pressure is low. How does it help the engine?
A. It regulates the coolant flow to the engine
B. It supplies extra fuel to the engine
C. It forces more air into the engine for better combustion ✓
D. It reduces the engine oil pressure
Correct Answer: C
Additional Key Mechanic Diesel Questions with Official Answers:
Q.8 In a four-stroke diesel engine, the fuel is injected during the:
A. Suction stroke
B. Compression stroke ✓
C. Power stroke
D. Exhaust stroke
Correct Answer: B
Q.9 The main function of the fuel injection pump in a diesel engine is to:
A. Mix air and fuel
B. Deliver fuel at high pressure to the injectors at the correct time ✓
C. Cool the fuel
D. Filter the fuel only
Correct Answer: B
Q.10 Which of the following is a common cause of black smoke from a diesel engine exhaust?
A. Excess air in combustion
B. Incomplete combustion due to excess fuel or clogged air filter ✓
C. Too much coolant
D. Low engine oil level
Correct Answer: B
Q.11 The purpose of the glow plug in a diesel engine is to:
A. Provide spark for ignition
B. Heat the combustion chamber for easier starting in cold conditions ✓
C. Measure exhaust temperature
D. Control fuel quantity
Correct Answer: B
Q.12 In diesel engines, the compression ratio is typically in the range of:
A. 6:1 to 8:1
B. 10:1 to 12:1
C. 14:1 to 22:1 ✓
D. 4:1 to 6:1
Correct Answer: C
Q.13 Which instrument is commonly used to measure the specific gravity of battery electrolyte?
A. Thermometer
B. Hydrometer ✓
C. Manometer
D. Barometer
Correct Answer: B
Q.14 The component that converts the reciprocating motion of the piston into rotary motion is the:
A. Camshaft
B. Crankshaft ✓
C. Valve
D. Flywheel only
Correct Answer: B
— End of Document —
Prepared from official RRB ALP Stage-2 CBT-2 Mechanic Diesel (28 July 2026, Shift-1) question paper & answer key.
Correct options marked with bold ✓. Full options for remaining questions available in original PDF.
RRB ALP 2025 CBT 2 Mechanic Diesel Question Paper and Answer Key PDF English
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