RRB Assistant Loco Pilot - Trade-based questions for diploma-engineering candidates in mechanical, electrical, electronics and automobile engineering Online Test (MCQ Quiz)

1. Which of the following is a primary function of a transformer?

A) To increase the frequency of AC voltage B) To change the level of AC voltage C) To convert AC to DC voltage D) To regulate the power factor of a circuit

2. In a DC motor, the back EMF is proportional to:

A) Applied voltage B) Motor speed C) Load torque D) Armature resistance

3. Which type of coupling is used to connect two shafts that are not perfectly aligned?

A) Flange coupling B) Muff coupling C) Universal coupling D) Rigid coupling

4. What is the unit of kinematic viscosity?

A) Pascal-second B) Stokes C) Newton per square meter D) Joule per second

5. Which of the following is a characteristic of a series DC generator?

A) Constant voltage output B) Voltage increases with load C) Voltage decreases with load D) Constant current output

6. What is the purpose of a commutator in a DC motor?

A) To increase torque B) To reverse the direction of current in the armature winding C) To regulate speed D) To reduce sparking

7. Which type of bearing is best suited for high radial loads and moderate axial loads?

A) Ball bearing B) Roller bearing C) Thrust bearing D) Plain bearing

8. What does the term 'Pascal's Law' relate to?

A) Pressure in fluids B) Heat transfer C) Electrical resistance D) Mechanical stress

9. Which type of welding uses a non-consumable tungsten electrode?

A) SMAW (Shielded Metal Arc Welding) B) GMAW (Gas Metal Arc Welding) C) GTAW (Gas Tungsten Arc Welding) D) FCAW (Flux-Cored Arc Welding)

10. What is the primary purpose of a flywheel in an engine?

A) To increase power output B) To smooth out rotational speed fluctuations C) To cool the engine D) To improve fuel efficiency

11. In electronics, what does a diode primarily do?

A) Amplifies signals B) Stores electrical energy C) Allows current to flow in only one direction D) Generates AC voltage

12. What is the function of a capacitor in an AC circuit?

A) To oppose changes in voltage B) To oppose changes in current C) To store energy in an electric field D) To convert AC to DC

13. Which of the following is a measure of the opposition to current flow in an AC circuit?

A) Resistance B) Inductance C) Capacitance D) Impedance

14. What is the main component of a typical transistor?

A) One semiconductor layer B) Two semiconductor layers C) Three semiconductor layers D) Four semiconductor layers

15. In a three-phase induction motor, what is the purpose of the stator winding?

A) To provide mechanical support B) To generate a rotating magnetic field C) To connect the motor to the power supply D) To dissipate heat

16. What is the term for the process of removing impurities from a metal by heating it below its melting point?

A) Smelting B) Refining C) Annealing D) Tempering

17. Which type of heat treatment is used to increase the hardness and strength of steel by heating and rapid cooling?

A) Normalizing B) Hardening C) Tempering D) Annealing

18. What is the primary function of the crankshaft in an internal combustion engine?

A) To control valve timing B) To convert reciprocating motion of pistons into rotational motion C) To ignite the fuel-air mixture D) To supply fuel to the cylinders

19. Which component of a car's braking system converts hydraulic pressure into mechanical force?

A) Brake pedal B) Brake fluid C) Brake caliper/wheel cylinder D) Brake lines

20. What is the purpose of a catalytic converter in an automobile?

A) To improve engine cooling B) To reduce harmful emissions C) To increase fuel injection efficiency D) To enhance ignition timing

21. Which type of engine typically uses spark plugs for ignition?

A) Diesel engine B) Gasoline (Petrol) engine C) Steam engine D) Jet engine

22. What does the term 'viscosity' measure?

A) The density of a fluid B) The resistance of a fluid to flow C) The surface tension of a fluid D) The compressibility of a fluid

23. Which law states that for every action, there is an equal and opposite reaction?

A) Newton's First Law B) Newton's Second Law C) Newton's Third Law D) Archimedes' Principle

24. What is the function of a rectifier in an electrical system?

A) To convert AC to DC B) To convert DC to AC C) To increase voltage D) To reduce current

25. Which type of motor is commonly used in applications requiring variable speed control?

A) DC series motor B) DC shunt motor C) Synchronous motor D) Variable frequency drive (VFD) controlled induction motor

26. What is the purpose of a governor in a prime mover?

A) To control fuel supply B) To regulate speed under varying loads C) To manage lubrication D) To monitor exhaust temperature

27. In metallurgy, what is annealing primarily used for?

A) To increase hardness B) To reduce brittleness and improve ductility C) To create a protective surface layer D) To increase tensile strength

28. Which automotive system is responsible for delivering fuel to the engine's cylinders?

A) Ignition system B) Exhaust system C) Fuel system D) Cooling system

29. What is the function of the alternator in a car?

A) To start the engine B) To charge the battery and power electrical systems while the engine is running C) To control the engine's speed D) To provide braking force

30. What does Ohm's Law describe the relationship between?

A) Voltage, current, and resistance B) Power, voltage, and current C) Charge, voltage, and capacitance D) Frequency, inductance, and capacitance

31. Which electronic component acts as a switch and amplifier?

A) Resistor B) Capacitor C) Inductor D) Transistor

32. What is the primary advantage of using a three-phase AC power system over a single-phase system?

A) Simpler wiring B) More efficient power transmission and generation of rotating magnetic fields C) Lower voltage requirements D) Easier voltage regulation

33. What is the term for the maximum stress a material can withstand before it begins to deform permanently?

A) Ultimate tensile strength B) Yield strength C) Elastic limit D) Fatigue strength

34. Which manufacturing process involves forcing molten metal into a mold cavity?

A) Forging B) Extrusion C) Casting D) Rolling

35. What is the function of the radiator in an automobile's cooling system?

A) To heat the engine oil B) To transfer heat from the coolant to the surrounding air C) To store excess coolant D) To regulate the coolant flow rate

36. Which type of gear is used to transmit motion between two non-parallel shafts?

A) Spur gear B) Helical gear C) Bevel gear D) Worm gear

37. What is the unit of electrical power?

A) Volt B) Ampere C) Ohm D) Watt

38. In a semiconductor, doping is done to:

A) Increase its melting point B) Increase its electrical conductivity C) Decrease its physical strength D) Make it non-conductive

39. What is the primary role of an amplifier in an electronic circuit?

A) To reduce signal amplitude B) To increase signal amplitude C) To filter out unwanted frequencies D) To rectify AC signals

40. Which type of AC generator produces voltage and frequency that are directly proportional to its speed?

A) Induction generator B) Permanent magnet alternator C) Synchronous generator D) DC generator

41. What is the phenomenon where a changing magnetic field induces an electromotive force (EMF) in a conductor?

A) Ohm's Law B) Joule Heating C) Electromagnetic Induction D) Capacitance

42. Which of the following is a common method for hardening steel?

A) Annealing B) Normalizing C) Quenching and tempering D) Stress relieving

43. What is the purpose of the clutch in a manual transmission vehicle?

A) To provide engine braking B) To allow the engine to be disconnected from the transmission temporarily C) To change gear ratios D) To lubricate the transmission gears

44. Which component in a car's suspension system absorbs shocks and provides a smoother ride?

A) Spring B) Shock absorber (damper) C) Control arm D) Ball joint

45. What is the term for the measure of how much a material resists scratching or abrasion?

A) Toughness B) Hardness C) Ductility D) Brittleness

46. Which law governs the relationship between the flow rate of a fluid and the pressure difference across a pipe?

A) Newton's Law of Viscosity B) Bernoulli's Principle C) Hagen-Poiseuille Equation D) Archimedes' Principle

47. What is the function of a transformer's core?

A) To provide electrical insulation B) To conduct the magnetic flux between the windings C) To dissipate heat generated in the windings D) To increase the voltage rating

48. Which type of circuit breaker uses a bimetallic strip to trip the circuit?

A) Magnetic circuit breaker B) Thermal circuit breaker C) Hydraulic circuit breaker D) Electronic circuit breaker

49. What is the main purpose of the rotor in an AC induction motor?

A) To generate voltage B) To create a rotating magnetic field C) To convert electrical energy into mechanical energy D) To provide magnetic flux

50. In automotive terms, what does 'engine displacement' refer to?

A) The total volume swept by all pistons in one engine cycle B) The volume of fuel injected per cycle C) The volume of exhaust gases produced D) The volume of the cooling system

Trade-based questions for diploma-engineering candidates in mechanical, electrical, electronics and automobile engineering - Online Test

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