Mechanical Engineering - Objective

Mechanical Engineering - Objective

1.    Instantaneous centre of a body rolling without sliding on a stationary curved surface lies
    1) at the point of contact
    2) on the common normal at the point of contact
    3) on the common tangent at the point of contact
    4) at the center of curvature of the stationary surface.
2.    In terms of Poisson's ratio(m), the ratio of Young's Modulus(E) to Shear Modulus(G) of elastic materials is
    1) 2(1 + m )    2) 2(1 - m)

    3)      4)  
3.    A block of steel is loaded by a tangential force on its top surface while the bottom surface is held rigidly. The deformation of the block is due to




    
    1) shear only    2) bending only
    3) shear and bending
    4) torsion
4.    The total extension of the bar loaded as shown in the figure is




    
    A = Area of cross-section
    E = Modulus of Elasticity
    1) 10 × 30/AE    2) 26 × 10/AE
    3) 9 × 30/AE    4) 30 × 22/AE
5.    The maximum bending moment in a simply supported beam of length L loaded by a concentrated load 'W' at the midpoint is given by

    1) WL        2)

    3)         4)
6.    The mechanism used in a shaping machine is
    1) a closed 4-bar chain having 4 revolute pair
    2) a closed 6-bar chain having 6 revolute pair
    3) a closed 4-bar chain having 2 revolute and 2 sliding pairs
    4) an invasion of the single slider-crank chain
7.    The speed of an engine varies from 210 rad/s to 190 rad/s. During cycle the change in kinetic energy is found to be 400Nm. The inertia of the fly wheel in Kgm2 is
    1) 0.10        2) 0.20
    3) 0.30        4) 0.40
8.    The minimum number of teeth on the pinion to operate without interference in standard full height involute teeth gear mechanism with 200 pressure angle is
    1) 14        2) 12
    3) 18        4) 32
9.    Axial operation claw clutches having self-locking tooth profile
    1) can be disengaged at any speed
    2) can be disengaged only unloaded
    3) can be engaged only when unloaded
    4) can work only with load.
10.    The total number of instantaneous centers for a mechanism consisting of 'n' links is

    1)         2) n

    3)         4)
11.    Sensitiveness of a governor is defined as
    1) Range of speed/Mean speed
    2) Mean speed/Range of speed
    3) Mean speed × Range of speed
    4) None
12.    In a fillet welded joint, the weakest area of the weld is
    1) toe        2) root
    3) throat        4) face
13.    Which of the following is not a friction clutch?
    1) Disc or plate clutch
    2) Cone clutch    3) Centrifugal clutch
    4) Jaw clutch
14.    The dimension of surface tension is
    1) N/m2        2) J/m
    3) J/M2        4) W/m
15.    Kaplan turbine is
    1) A high head mixed flow turbine.
    2) A low head axial flow turbine.
    3) An outward flow reaction turbine.
    4) An impulse inward flow turbine.
16.    What is the unit of dynamic viscosity of a fluid termed 'poise' equivalent to
    1) dyne/cm2
    2) gm - s/cm2    3) dyne - s/cm2    4) gm-cm/s
17.    The pressure pascal corresponding to 3 cm column of Mercury is
    1) 7988.6        2) 3994.3
    3) 2662.8        4) 1331.4
18.    An incompressible fluid flows radially outward from a line source in a steady manner. How does velocity in any radial direction vary?
    1) r        2) r2
    3) 1/r2        4) 1/r
19.    For a given discharge in a channel at critical depth
    1) the specific energy is minimum
    2) the specific energy is maximum
    3) the total energy is minimum
    4) the total energy is maximum.
20.    The drag force exerted by a fluid on a body immersed in the fluid is due to
    1) pressure and viscous forces
    2) pressure and gravity forces
    3) pressure and surface tension forces
    4) viscous and gravity forces.
21.    For a given heat flow and for the same thickness, the temperature drop across the material will be maximum for
    1) copper        2) steel
    3) glass wool    4) Refractory brick
22.    For an opaque surface, the absorptivity (a), transmissivity(t) and reflectivity(r) are related by the equation
    1) a + r = t    2) r + a + t = 0
    3) a + r  = 1    4) a + r = 0
23.    Heat pipe is widely used now a days because
    1) it acts as an insulator
    2) it acts as conductor and insulator
    3) it acts as super conductor
    4) it acts as fin
24.    This substance has the minimum value of thermal conductivity
    1) Air        2) Water
    3) Plastic        4) Rubber
25.    In case of liquids, what is the binary diffusion coefficient proportional to
    1) pressure only
    2) temperature only
    3) volume only    4) all the above
26.    If a closed system is undergoing an irreversible process, the entrophy of the system
    1) must increase
    2) always remains constant
    3) must decrease
    4) can increase, decrease or constant
27.    Maximum theoretical work obtainable when a system interacts to equilibrium with a reference environment is called
    1) Entropy    2) Enthalpy
    3) Energy    4) Rothalpy
28.    Which one of the following thermodynamic process approximates the steaming of food in a pressure cooker
    1) Isoenthalpic    2) Isobaric
    3) Isochoric    4) Isothermal
29.    Change in internal energy in reversible process occuring in a closed system is equal to the heat transferred if the process occurs at constant
    1) Pressure    2) Volume
    3) Tempetature    4) Enthalpy
30.    At critical point the enthalpy of vapourisation is
    1) dependent on temperature only
    2) maximum    3) minimum
    4) zero
31.    Global warming is caused by
    1) Ozone        2) Carbondioxide
    3) Nitrogen monoxide
    4) Carbon
32.    An industrial heat pump operates between the temperature of 270C and -130C. The rates of heat addition and heat rejection are 750W and 1000W respectively. The COP for the heat pump is
    1) 7.5        2) 6.5
    3) 4.0        4) 3.0
33.    A heat pump operating on carnot cycle pumps heat from a reservoir at 300k to a reservoir at 600k. The coefficient of performance is
    1) 1.5        2) 0.5
    3) 2        4) 1
34.    The refrigerant used for absorption refrigerator working heat from solar collectors is mixture of water and
    1) Carbondioxide
    2) Sulphurdioxide
    3) Lithium bromide
    4) freon 12
35.    Which type of value is generally used in reciprocating refrigerant compressors
    1) mushroom value
    2) puppet value    3) plate value
    4) throttle value
36.    The most widely used reinforcement in modern day FRP tennis racket is
    1) Glass        2) Carbon
    3) Aluminium    4) Magnesium
37.    For wire drawing operation, the work material should essentially be
    1) ductile        2) tough
    3) hard        4) malleable
38.    Small amount of carbonaceous material sprinkled on the inner surface of mould cavity is called
    1) backing sand
    2) facing sand    3) green sand
    4) dry sand
39.    Which one of the following lubricants is most suitable for drawing mild steel wires?
    1) Sodium stearate
    2) Water        3) Lime water
    4) Kerosene
40.    The proportion of Acetylene and Oxygen used in gas welding is
    1) 2:1        2) 1:1
    3) 1:2        4) 3:4

Answers
1) 1    2) 1    3) 3    4) 2    5) 3
6) 4    7) 1    8) 3    9) 3    10) 4
11) 2    12) 3    13) 4    14) 3    15) 2
16) 3    17) 2    18) 4    19) 1    20) 1
21) 3    22) 3    23) 3    24) 1    25) 4
26) 4    27) 3    28) 3    29) 2    30) 4
31) 2    32) 3    33) 3    34) 3    35) 3
36) 2    37) 1    38) 2    39) 3    40) 2