RailTel-RCIL Mechanical-Engineering Contributed by Shilpa Sreenivas updated on Aug 2019

RailTel-RCIL Mechanical Engg Questions with Answers and Explanation

 

RailTel-RCIL Mechanical Engg Question Paper

1. A thermodynamic system is considered to be an isolated one if

(A) Mains transfer and entropy change are zero
(B) Entropy change and energy transfer are zero
(C) Energy transfer and mass transfer are zero
(D) Mass transfer and volume change are zero
Ans: (C)

 

2. A closed system is one in which

(A) Mass does not cross boundaries of the system, though energy may do so
(B) Mass crosses the boundary but not the energy
(C) Neither mass nor energy cross the boundary of the system
(D) Both energy and mass cross the boundaries of the system

Ans: (A)

 

3. Air is being forced by the bicycle pump into a tyre against a pressure of 4-5 bars. A slow downward movement of the piston can be approximated as

(A) Isobaric process
(B) Adiabatic process
(C) Throttling process
(D) Isothermal process
Ans: (D)

 

4. Isentropic flow is

(A) Irreversible adiabatic flow
(B) Reversible adiabatic flow
(C) Ideal fluid flow
(D) Frictionless reversible flow
Ans: (B)

 

5. The cycle in which heat is supplied at constant volume and rejected at constant pressure is known as

(A) Dual combustion cycle
(B) Diesel cycle
(C) Atkinson cycle
(D) Rankine cycle
Ans: (C)

 

6. Air injection is IC engine refers to injection of

(A) Air only
(B) Liquid fuel only
(C) liquid fuel and air
(D) Supercharging air
Ans: (B)

 

7. Turbo prop-engine has the following additional feature over the turbojet :

(A) Propeller
(B) Diffuser
(C) Starting engine
(D) Turbine and combustion chamber
Ans: (A)

 

8. In the SI engine, highest UBHC concentration is observed during

(A) Maximum load
(B) Acceleration
(C) Deceleration
(D) Idling
Ans: (d)

 

9. Shielding in a nuclear power plant is done

(A) To protect against neutron and gamma rays
(B) To absorb excess neutrons
(C) To slow down the speed of fast moving neutrons
(D) To return the neutrons back into the core of the reactor
Ans: (A)

 

10. In the film established along a vertical plate during condensation of any vapour over the plates, the temperature distribution curve is

(A) Concave upwards
(B) Concave downwards
(C) Parabolic
(D) Straight line
Ans: (D)

 

11. In spite of large heat transfer coefficients in boiling liquids, cavities are used advantageously when entire surface is exposed to

(A) Nucleate boiling
(B) Film boiling
(C) Transition boiling
(D) Pool boiling
Ans: (C)

 

12. What is the unit of dynamic viscosity of a fluid termed 'poise' equivalent to?

(A) dyne/cm2
(B) gm s/cm
(C) dyne s/cm2
(D) gm-cm/s
Ans:C

 

13. If the surface tension of water-air interface is 0.073 N/m, the gauge pressure inside a rain drop of 1 mm diameter will be:

(A) 0.146N/m2
(B) 73N/m2
(C) 146N/m2
(D) 292 N/m2
Ans:D


Ex:P = 4σ/d = 4*0.073/.001 = 292N/m2

14. Which one of the following sets of conditions clearly apply to an ideal fluid?

(A) Viscous and compressible
(B) Non-viscous and incompressible
(c) Non-viscous and compressible
(d) Viscous and incompressible
Ans:B

 

15. Fluids that require a gradually increasing shear stress to maintain a constant strain rate are known as

(A) Rhedopectic fluids
(B) Thixotropic fluids
(C) Pseudoplastic fluids
(D) Newtonian fluids

Ans:A

 

16. At the interface of a liquid and gas at rest, the pressure is:

(A) Higher on the concave side compared to that on the convex side
(B) Higher on the convex side compared to that on the concave side
(C) Equal to both sides
(D) Equal to surface tension divided by radius of curvature on both sides
Ans:A

 

17. Willans line represents

(A) Total steam consumption vs power output with throttle governing
(B) Total steam consumption vs power output with cutoff governing
(C) Behaviour of supersaturated steam through nozzles
(D) Condensation of steam while flowing through the turbine
Ans: (A)

 

18. In a locomotive boiler, the draught is produced by

(A) Chimnay
(B) ID fan
(C) FD fan
(D) Steam jet
Ans: (D)

 

19. A Kaplan turbine is a

(A) Outward flow reaction turbine
(B) Inward flow impulse turbine
(C) Low head axial flow turbine
(D) High head mixed flow turbine
Ans: (C)

 

20. Navier – stokes equations are useful in the analysis of

(A) Turbulent flows
(B) Vortex flows
(C) Viscous flows
(D) Rotatioal flows
Ans: (C)

 

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