Mechanical Engineers Recruitment Exam Question Paper

Q1. The buckling load for a column pinned at both ends is 10 kN. If the ends are fixed, the buckling load changes to
(1) 40 kN
(2) 2·5 kN
(3) 5 kN
(4) 20 kN
Q2. A 30 mm hole/shaft assembly results in minimum and maximum clearance of 0·03 mm and 0·3 mm respectively. The hole has a unilateral tolerance with zero fundamental deviation. If the tolerance of
the shaft is 0·08 mm, the maximum size of the hole is
(1) 30·11 mm
(2) 30·16 mm
(3) 30·19 mm
(4) 30·27 mm

Q3. Consider the following drives :
A. V-belt
B. Flat belt
C. Toothed belt
D. Round belt
Which of the above is/are positive drive(s) ?
Select the code for the correct answer from the options given below :
(1) A and B only
(2) B only
(3) C only
(4) C and D only


Q4. Bolts in the flanged end of a pressure vessel are usually pre-tensioned. Indicate which of the following
statements is not true :
(1) Pre-tensioning helps to seal the pressure vessel.
(2) Pre-tensioning reduces the maximum tensile stress in the bolts.
(3) Pre-tensioning increases the fatigue life of the bolts.
(4) Pre-tensioning helps to reduce the effect of pressure pulsations in the pressure vessel.

Q5. Which of the following are the third inversions of slider crank mechanism ?
A. Oscillating cylinder engine
B. Hand pump
C. Rotary engine
D. Crank and slotted lever
Select the code for the correct answer from the options given below :
(1) A and B only
(2) A and D only
(3) A, B and D only
(4) All of the above

Q6. Which of the following governors is/are not suitable for high speeds ?
A. Watt Governor
B. Hartnell Governor
C. Hartung Governor
D. Wilson-Heartnell Governor

Select the code for the correct answer
from the options given below :
(1) C only
(2) A only
(3) Both A and C
(4) Both C and D

Q7. Net Strain Gauge is
(1) An active device and converts mechanical displacement into change of resistance.
(2) A passive device and converts mechanical displacement into change of resistance.
(3) A passive device and converts electrical displacement into change of resistance.
(4) An active device and converts electrical displacement into change of resistance.

Q8. Which theory(ies) of failure will you use for aluminium under static loading ?
A. Principal Stress Theory
B. Principal Strain Theory
C. Strain Energy Theory
D. Maximum Shear Stress Theory
Select the code for the correct answer from the options given below :
(1) A and D only
(2) C and D only
(3) B only
(4) D only

Q9. Which of the following statements is true ?
(1) Below 910C, pure iron exists in FCC crystal structure.
(2) Between 1537C and 1400C, iron exists as pearlite.
(3) In the iron-carbon equilibrium diagram the eutectic point is at 6·67% of C.
(4) None of these

Q10. The effect of cobalt in a steel alloy is
(1) to increase red hardness and sustain hardness during tempering.
(2) to increase softness and weldability.
(3) to promote deoxidisation and nitriding.
(4) to promote grain growth and machinability.


Q11. The main objects of annealing are
(1) To refine grain size and to relieve internal stresses.
(2) To alter electrical and magnetic properties.
(3) To remove gases trapped in the metal during initial casting.
(4) All of the above

Q12. By the law of belting
(1) Two non-parallel shafts can be run in either direction without any intermediation.
(2) A guide pulley helps two non-parallel shafts to run in either direction.
(3) The centre line of the belt when it approaches an idler pulley should be at the edge of the plane.
(4) All of the above

Q13. In an S.I. engine, when most economical mixture is supplied, the colour of exhaust gases can be expected to be
(1) Bluish
(2) Dark red
(3) Dark blue and reddish yellow
(4) White

Q14. For carbon-carbon composites, the following statement(s) is/are true :
(1) C-C composites are structures in which both matrix and the reinforcement are carbon.
(2) C-C composites have high temperature strength and toughness.
(3) The high cost of C-C composites is a major issue.
(4) All of the above

Q15. Consider the following statements in relation to composite materials.
A. A composite material is a structural material created synthetically or  artificially by combining two ormore materials having dissimilar characteristics.
B. The constituents are combined at macroscopic level and are not soluble in each other.
C. One constituent is called as matrix phase and the other is called as reinforcing phase.
D. Reinforcing phase is embedded in the matrix phase.
Which of the above statements is/are correct ? Select the code for the correct answer from the options given below :
(1) A only
(2) A, B and C only
(3) A and C only
(4) None of the above

Q16. A dehumidifier is required in
(1) A winter air-conditioning system
(2) A summer air-conditioning system
(3) Filters for removing dust particles
(4) A duct where air is circulated into required space

Q17. Which of the following would not increase the rate of heat transferred from a heater pipe ?
(1) Insulating with materials whose thickness is below that of critical thickness for insulation.
(2) Providing cooling jackets over the heater pipe surface.
(3) Providing heat exchangers.
(4) Covering heater pipe with another pipe whose thermal conductivity is smaller in number and 50 mm
thick.

Q18. A screw thread is obtained (1) When the hypotenuse of a right-angled triangle is wrapped
around the circumference of a cylinder.
(2) When a point moves on the circumference of a cylinder at a ratio of diameter to the pitch of thread.

(3) When a line moves on the circumference of a cylinder with an angle parallel to its axis.
(4) When one of the sides of an equilateral triangle is wrapped around the circumference of a
cylinder.

Q19.In the open channels, the specific energy is the
(1) total energy per unit discharge
(2) total energy measured with respect to the datum passing through the bottom of the channel
(3) total energy measured above the horizontal datum
(4) total energy per velocity of flow

Q20. For a perfect incompressible liquid flowing in a continuous stream, the total energy of a particle remains the same while the particle moves from one point to another. This statement is called
(1) Continuity equation
(2) Bernoulli’s equation
(3) Pascal’s law
(4) Archimedes’ principle

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