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MCQOPTIONS
This section includes 2670 Mcqs, each offering curated multiple-choice questions to sharpen your Railways knowledge and support exam preparation. Choose a topic below to get started.
| 51. |
The effect of friction on flow of steam through a nozzle is to: |
| A. | Decrease the mass flow rate and to increase the wetness at the exit |
| B. | Increase the mass flow rate and to increase the exit temperature |
| C. | Decrease the mass flow rate and to decrease the wetness of the steam |
| D. | Increase the exit temperature, without any effect on the mass flow rate. |
| Answer» D. Increase the exit temperature, without any effect on the mass flow rate. | |
| 52. |
Earliest finish time can be regarded as: |
| A. | EST + duration of activity |
| B. | EST \[-\] duration of activity |
| C. | LFT + duration of activity |
| D. | LET \[-\] duration of activity |
| Answer» B. EST \[-\] duration of activity | |
| 53. |
According to the maximum shear stress theory failure, permissible twisting moment in a circular shaft is T. The permissible twisting moment in the same shaft as per the maximum principal stress 6 theory of failure will be |
| A. | T/2 |
| B. | T |
| C. | \[\sqrt{2T}\] |
| D. | 2T |
| Answer» E. | |
| 54. |
If a number of forces act on a rigid body, each force may he replaced by an equal and parallel force acting through a Fixed point, together with a couple. For the rigid body to be in equilibrium: |
| A. | The resultant force at the fixed point must be Zero |
| B. | The resultant couple on the body must be zero |
| C. | Both resultant force and couple must be zero |
| D. | None of the above need be zero |
| Answer» D. None of the above need be zero | |
| 55. |
Match List-I (Surfaces with Orientations) with List-II (Equivalent Emissivity) and select the correct answer using the codes given below the lists: List I (Surfaces with orientations) List-II (Equivalent Emissivity) A. Infinite parallel planes 1. \[{{\in }_{1}}\] B. Body 1 completely enclosed by body 2 but body 1 is very small 2. \[\frac{1}{\frac{1}{{{\in }_{1}}}+\frac{1}{{{\in }_{2}}}-1}\] C. Radiation exchange between two small gray bodies 3. \[\frac{1}{\frac{1}{{{\in }_{1}}}+\left( \frac{{{A}_{1}}}{{{A}_{2}}} \right)\left( \frac{1}{{{\in }_{2}}}-1 \right)}\] D. Two concentric cylinders with large lengths 4. \[{{\in }_{1}}.{{\in }_{2}}\] Codes: |
| A. | A\[\to \]3, B\[\to \]1, C\[\to \]4, D\[\to \]2 |
| B. | A\[\to \]2, B\[\to \]4, C\[\to \]1, D\[\to \]3 |
| C. | A\[\to \]2, B\[\to \]1, C\[\to \]4, D\[\to \]3 |
| D. | A\[\to \]3, B\[\to \]4, C\[\to \]1, D\[\to \]2 |
| Answer» D. A\[\to \]3, B\[\to \]4, C\[\to \]1, D\[\to \]2 | |
| 56. |
The outer circle of spur gear is called: |
| A. | pitch circle |
| B. | base circle |
| C. | addendum circle |
| D. | dedeundum circle |
| Answer» C. addendum circle | |
| 57. |
Which of the following drive systems is used in computer numerically controlled machine tools? |
| A. | Stepper motor |
| B. | Amorphous structure |
| C. | Thyristor controlled DC motor |
| D. | Servo controlled pneumatic drives |
| Answer» E. | |
| 58. |
What is the correct statement regarding normal shock wave in a gas? |
| A. | Normal shock is reversible |
| B. | The downstream flow as well as upstream flow is supersonic |
| C. | The entropy increases across the shock |
| D. | The entropy remains constant |
| Answer» D. The entropy remains constant | |
| 59. |
If a shaft made from ductile material is subjected to combined bending and twisting moments, calculation based on which one of the following failure theories would give the most conservative value? |
| A. | Maximum principal stress theory |
| B. | Maximum shear stress theory |
| C. | Maximum strain energy theory |
| D. | Maximum distortion energy theory |
| Answer» C. Maximum strain energy theory | |
| 60. |
In an axial flow co impresser stage, air enters and leaves the stage axially. If the whirl component of the air leaving the rotor is half the mean peripheral velocity of the rotor Wades, then the degree of reaction will be: |
| A. | 1.00 |
| B. | 0.75 |
| C. | 0.50 |
| D. | 0.25 |
| Answer» E. | |
| 61. |
In free expansion of a gas between two equilibrium states, the work transfer involved: |
| A. | Can be calculated by joining the two states on\[p-v\]Coordinates by any path and estimating the area below |
| B. | Can be calculated by joining the two states by quasi-static path and then finding the area below |
| C. | Is zero |
| D. | Is equal to heat generated by friction during? Expansion |
| Answer» D. Is equal to heat generated by friction during? Expansion | |
| 62. |
If Poisson's ratio for a material is 0.5, then the elastic modulus for the material is: |
| A. | Three times its shear modulus |
| B. | Four times its shear modulus |
| C. | Equal to its shear modulus |
| D. | Indeterminate. |
| Answer» E. | |
| 63. |
The natural frequency of transverse vibration of a massless beam of length L having a mass m attached at its midspan is given by: (El is the flexural rigidity of the beam) |
| A. | \[{{\left( \frac{m{{l}^{3}}}{48EI} \right)}^{\frac{1}{2}}}\text{rad/s}\] |
| B. | \[{{\left( \frac{48m{{l}^{3}}}{EI} \right)}^{\frac{1}{2}}}\text{rad/s}\] |
| C. | \[{{\left( \frac{48EI}{m{{L}^{3}}} \right)}^{\frac{1}{2}}}\text{rad/s}\] |
| D. | \[{{\left( \frac{3EI}{m{{L}^{3}}} \right)}^{\frac{1}{2}}}\text{rad/s}\] |
| Answer» D. \[{{\left( \frac{3EI}{m{{L}^{3}}} \right)}^{\frac{1}{2}}}\text{rad/s}\] | |
| 64. |
or a non-flow constant pressure process, the heat exchange is equal to: |
| A. | Zero |
| B. | The work done |
| C. | The change in internal energy |
| D. | The change in enthalpy |
| Answer» E. | |
| 65. |
A gas turbine cycle with infinitely large number of stages during compression and expansion approaches: |
| A. | Stirling cycle |
| B. | Atkinson cycle |
| C. | Ericsson cycle |
| D. | Brayton cycle |
| Answer» C. Ericsson cycle | |
| 66. |
The thrust of a jet propulsion power unit can be increased by: |
| A. | Injecting water into compressor |
| B. | Burning fuel after gas turbine |
| C. | Injecting ammonia into the combustion chamber |
| D. | all of the above, |
| Answer» B. Burning fuel after gas turbine | |
| 67. |
When bending moment M and torque T is applied on a shaft then equivalent torque is: |
| A. | M+T |
| B. | \[\sqrt{{{M}^{2}}+{{T}^{2}}}\] |
| C. | \[\frac{1}{2}\sqrt{{{M}^{2}}+{{T}^{2}}}\] |
| D. | \[\frac{1}{2}\left( m+\sqrt{{{M}^{2}}+{{T}^{2}}} \right)\] |
| Answer» C. \[\frac{1}{2}\sqrt{{{M}^{2}}+{{T}^{2}}}\] | |
| 68. |
Given that \[p\,=\] chain pitch C = Centre distance N, n = number of teeth on large and small sprocket respectively, The length of chain in terms of pitches can be approximated by: |
| A. | \[\frac{2C}{P}\] |
| B. | \[\frac{2C}{P}+(N+n)/2\] |
| C. | \[\frac{2C}{P}+\left[ \frac{N+n}{2\pi } \right]\frac{p}{C}\] |
| D. | \[\frac{2C}{P}+\frac{N+n}{2p}{{\left[ \frac{N-n}{2p} \right]}^{2}}\,\frac{p}{C}\] |
| Answer» E. | |
| 69. |
Which one of the following types of compressors is mostly used for supercharging of I.C. engines? |
| A. | Radial flow compressor |
| B. | Axial flow compressor |
| C. | Roots blower |
| D. | Reciprocating compressor |
| Answer» C. Roots blower | |
| 70. |
The volumetric air content of a tyre at \[27{}^\circ C\] and at 2 bar is 30 litres. If one morning the temperature dips \[-\,\,3{}^\circ C,\] then the air pressure in the tyre would be: |
| A. | 1.8 bar |
| B. | 11 bar |
| C. | 0.8 bar |
| D. | The same as at \[27{}^\circ C\] |
| Answer» B. 11 bar | |
| 71. |
One kg of a perfect gas is compressed from pressure \[{{p}_{1}}\] to pressure \[{{p}_{2}}\] by 1. Isothermal process 2. Adiabatic process 3. The law \[p{{v}^{1.1}}\,\,=\,\] constant The correct sequence of these processes in increasing order of their work requirement is: |
| A. | 1, 2, 3 |
| B. | 1, 3, 2 |
| C. | 2, 3, 1 |
| D. | 3, 1, 2. |
| Answer» B. 1, 3, 2 | |
| 72. |
In S.H.M. with respect to the displacement vector, the positions of Velocity vector and Acceleration vector will he respectively: |
| A. | \[180{}^\circ \]and \[90{}^\circ \] |
| B. | \[90{}^\circ \]and\[180{}^\circ \] |
| C. | \[0{}^\circ \]and \[90{}^\circ \] |
| D. | \[90{}^\circ \]and\[0{}^\circ \] |
| Answer» C. \[0{}^\circ \]and \[90{}^\circ \] | |
| 73. |
When a slider moves with a velocity V on a link rotating at an angular speed of co, the Corioli's component of acceleration is given by: |
| A. | \[\sqrt{2v\omega }\] |
| B. | \[v\omega \] |
| C. | \[\frac{v\omega }{2}\] |
| D. | \[2v\omega \] |
| Answer» E. | |
| 74. |
A shaft, supported on two bearings at its ends, carries two flywheels 'L' apart. Mass moment of inertia of the two flywheels are \[{{l}_{a}}\] and \[{{l}_{b}}\] I being the polar moment of inertia of cross-sectional area of inertia of shaft. Distance \[{{l}_{a}}\] of the node of torsional vibration of the shaft from the flywheel la is \[{{l}_{a}}\] given by: |
| A. | \[{{l}_{a}}=\frac{L{{l}_{b}}}{{{I}_{a}}+{{I}_{b}}}\] |
| B. | \[{{l}_{a}}=\frac{L{{l}_{a}}}{{{I}_{a}}+{{I}_{b}}}\] |
| C. | \[{{l}_{a}}=\frac{L{{l}_{b}}}{{{I}_{a}}+{{I}_{b}}-1}\] |
| D. | \[{{l}_{a}}=\frac{L{{l}_{a}}}{{{I}_{a}}+{{I}_{b}}-1}\] |
| Answer» B. \[{{l}_{a}}=\frac{L{{l}_{a}}}{{{I}_{a}}+{{I}_{b}}}\] | |
| 75. |
The transmitted force through a mass-spring damper system will be greater than that transmitted through rigid supports for all values of-damping factors, if the frequency ratio \[\left( \frac{\omega }{{{\omega }_{n}}} \right)\] is: |
| A. | More than \[\sqrt{2}\] |
| B. | less than \[\sqrt{2}\] |
| C. | Equal to one |
| D. | less than one |
| Answer» C. Equal to one | |
| 76. |
The most common type of absorption system in use in industrial applications is based on the refrigerant absorbent combination of: |
| A. | Air-Water |
| B. | Lithium bromide-air |
| C. | Carbon dioxide-Water |
| D. | Ammonia-Water |
| Answer» E. | |
| 77. |
Solar energy be directly used in: |
| A. | Vapour compression refrigeration system |
| B. | Vapour absorption refrigeration system |
| C. | Air refrigeration system |
| D. | Jet refrigeration system |
| Answer» C. Air refrigeration system | |
| 78. |
The equation \[\phi =\frac{{{p}_{v}}}{ps}\] is used to calculate the \[({{p}_{v}}=\] partial pressure of water vapour in moist air at a given temperature \[{{p}_{s}}=\] saturation pressure of water vapour at the same temperature) |
| A. | Relative humidity |
| B. | Degree of saturation |
| C. | Specific humidity |
| D. | Absolute humidity |
| Answer» B. Degree of saturation | |
| 79. |
The suction pressure is 1 bar and delivery pressure is 125 bar. What is the ideal intermediate pressure at the end of first stage for a 3-stage air compressor? |
| A. | 25 bar |
| B. | 5 bar |
| C. | 10 bar |
| D. | 20 bar |
| Answer» C. 10 bar | |
| 80. |
Which one of the following is correct? In a gas turbine cycle with regeneration |
| A. | Pressure output increases |
| B. | Work output decreases |
| C. | Thermal efficiency increases |
| D. | Heat input increases |
| Answer» D. Heat input increases | |
| 81. |
In finish machining of an island on a casting with CNC milling machine, an end mill with 10 mm diameter is employed. The comer points of the island arc represented by (0, 0), (0, 30), (50, 30) and (50, 0). by applying cutter radius right compensation, the trajectory of the cutter will be: |
| A. | \[(-5,\,0),\]\[(-\,5,\,35),\]\[(55,\,35),\]\[(55,\,-5),\]\[(-5,\,-5)\] |
| B. | \[(0,-\,5),\]\[(55,\,-5),\]\[(55,\,35),\]\[(-\,5,\,35),\]\[(-5,\,-5)\] |
| C. | \[(5,\,5),\]\[(5,\,25),\]\[(45,25),\]\[(45,5),\]\[(5,\,5)\] |
| D. | \[(5,\,5),\]\[(45,\,5),\,\]\[(45,\,25),\] \[(5,\,25),\]\[(5,\,5)\] |
| Answer» C. \[(5,\,5),\]\[(5,\,25),\]\[(45,25),\]\[(45,5),\]\[(5,\,5)\] | |
| 82. |
Which one of the following is an Open Pair? |
| A. | Ball and socket joint |
| B. | Journal bearing |
| C. | Lead screw and nut |
| D. | Cam and follower |
| Answer» E. | |
| 83. |
In a 4-stroke I.C engine, the turning moment during the compression stroke is: |
| A. | Positive throughout |
| B. | Negative throughout |
| C. | Positive during major portion of the stroke |
| D. | Negative during major portion of the stroke |
| Answer» E. | |
| 84. |
Match List-I (Applications) with List-II (drive element) and select the correct answer using the given below the lists: List-I List-II A. Automobile differential 1. Flat belt B. Bicycle 2. belt C. Planning machine 3. Chain drive D. Radiator fan of automobile motion 4. Gear drive Codes: |
| A. | A\[\to \]4, B\[\to \]3, C\[\to \]1, D\[\to \]2 |
| B. | A\[\to \]1, B\[\to \]3, C\[\to \]4, D\[\to \]2 |
| C. | A\[\to \]4, B\[\to \]2, C\[\to \]1, D\[\to \]3 |
| D. | A\[\to \]1, B\[\to \]2, C\[\to \]4, D\[\to \]3 |
| Answer» B. A\[\to \]1, B\[\to \]3, C\[\to \]4, D\[\to \]2 | |
| 85. |
The critical pressure ratio \[\left( \frac{{{p}_{2}}}{{{p}_{1}}} \right)\] for maximum discharge through a nozzle is: |
| A. | \[{{\left( \frac{2}{n+1} \right)}^{\left( \frac{n\,\,-\,\,1}{n} \right)}}\] |
| B. | \[{{\left( \frac{2}{n+1} \right)}^{\left( \frac{n}{n\,\,-\,\,1} \right)}}\] |
| C. | \[{{\left( \frac{2}{n-1} \right)}^{\left( \frac{n}{n\,\,+\,\,1} \right)}}\] |
| D. | \[{{\left( \frac{2}{n-1} \right)}^{\left( \frac{n\,\,+\,\,1}{n} \right)}}\] |
| Answer» C. \[{{\left( \frac{2}{n-1} \right)}^{\left( \frac{n}{n\,\,+\,\,1} \right)}}\] | |
| 86. |
Match List-I with List-II and select the correct answer using the codes given below the lists: List-I (Parameter) List-II (Property) A. Volume 1. Path function B. Density 2. Intensive property C. Pressure 3. Extensive property D. Work 4. Point function Codes: |
| A. | A\[\to \]3, B\[\to \]2, C\[\to \]4, D\[\to \]1 |
| B. | A\[\to \]3, B\[\to \]2, C\[\to \]1, D\[\to \]4 |
| C. | A\[\to \]2, B\[\to \]3, C\[\to \]4, D\[\to \]1 |
| D. | A\[\to \]2, B\[\to \]3, C\[\to \]1, D\[\to \]4 |
| Answer» B. A\[\to \]3, B\[\to \]2, C\[\to \]1, D\[\to \]4 | |
| 87. |
Match List-I with List-II and select the correct answer using the codes' giver below the lists: List-I List-II A. Ductility 1. Impac test B. Toughness 2. Fatigue test C. Endurance limit 3. Tension test D. Resistance to penetration 4. Hardness test Codes: |
| A. | A\[\to \]3, B\[\to \]2, C\[\to \]1, D\[\to \]4 |
| B. | A\[\to \]4, B\[\to \]2, C\[\to \]1, D\[\to \]3 |
| C. | A\[\to \]3, B\[\to \]1, C\[\to \]2, D\[\to \]4 |
| D. | A\[\to \]4, B\[\to \]1, C\[\to \]2, D\[\to \]3 |
| Answer» D. A\[\to \]4, B\[\to \]1, C\[\to \]2, D\[\to \]3 | |
| 88. |
If a material had a modulus of elasticity of \[2.1\times {{10}^{6}}\text{kgf/c}{{\text{m}}^{\text{2}}}\] and a modulus of rigidity of \[0.8\times {{10}^{6}}\text{kgf/c}{{\text{m}}^{\text{2}}}\] then the approximate value of the Poisson's ratio of the material would be: |
| A. | 0.26 |
| B. | 0.31 |
| C. | 0.47 |
| D. | 5 |
| Answer» C. 0.47 | |
| 89. |
What is/are the effect (s) of super saturation in nozzle flow? 1. It increases the mass flow. 2. It increases friction in the nozzle. 3. It increases exit velocity. 4. It reduces dryness fraction of steam. Select the correct answer using the code given below: |
| A. | 1 only |
| B. | 1 and 3 |
| C. | 1, 2 and 4 |
| D. | 3 only |
| Answer» D. 3 only | |
| 90. |
Consider the following statements: A tube section diverging in the direction of fluid flow can be used as 1. Supersonic nozzle 2. Subsonic nozzle 3. Supersonic diffuser 4. Subsonic diffuser Which of the statements given above is/are correct? |
| A. | 1 only |
| B. | 1 and 4 |
| C. | 3 only |
| D. | 2 and 3 |
| Answer» C. 3 only | |
| 91. |
A reversible engine receives heat from a reservoir at \[700{}^\circ C\] and rejects heat at a temperature\[{{T}_{2}}\]. A second reversible engine operating on Carnot cycle receives heat rejected by the first engine and rejects heat to a sink at \[37{}^\circ C.\] If work output from each of the engines is equal, what is the value of temperature \[{{T}_{2}}\] ? |
| A. | 641.5 K |
| B. | 537 K |
| C. | 516 K |
| D. | 498.5 K |
| Answer» B. 537 K | |
| 92. |
The entropy of a mixture of pure gases is the sum of The entropies of constituents evaluated at: |
| A. | Temperature and pressure of the mixture |
| B. | Temperature of the mixture and the partial pressure of the constituents |
| C. | Temperature and volume of the mixture |
| D. | Pressure and volume of the mixture |
| Answer» B. Temperature of the mixture and the partial pressure of the constituents | |
| 93. |
This stagnation pressure rise in a centrifugal compressor stage takes place: |
| A. | Only in the diffuser |
| B. | In the diffuser and impeller |
| C. | Only in the impeller |
| D. | Only in the inlet guide vanes. |
| Answer» C. Only in the impeller | |
| 94. |
Consider the following statements: 1. Intercooling is effective only at lower pressure- ratios and high turbine inlet temperatures. 2. There is very little gain in thermal efficiency when intercooling is used without the benefit of regeneration. 3. With higher value of 'y' and \[{{c}_{p}}\] of the working fluid, will net power output of Brayton cycle will increase. Of these statements: |
| A. | 1, 2 and 3 are correct |
| B. | 1 and 2 are correct |
| C. | 1 and 3 are correct |
| D. | 2 and 3 are correct |
| Answer» E. | |
| 95. |
Large clearance volume in reciprocating compressor results in |
| A. | Reduced volume flow rate |
| B. | Increased volume flow rate |
| C. | Lower suction pressure |
| D. | Lower delivery pressure |
| Answer» E. | |
| 96. |
Consider the following statements: The form factor of a spur gear tooth depends upon the 1. Number of teeth 2. Pressure angle. 3. Addendum modification. 4. Circular pitch. Of these statements: |
| A. | 1 and 3 are correct |
| B. | 1 and 4 are correct |
| C. | 1, 2 and 3 are correct |
| D. | 1 and 4 are correct |
| Answer» D. 1 and 4 are correct | |
| 97. |
Atkinson gas engine has a special feature that |
| A. | isentropic compression and expansion are of equal stroke lengths |
| B. | isentropic compression is on a short stroke and the expansion on a longer stroke |
| C. | isentropic compression is on a longer stroke and the expansion on a short stroke |
| D. | it employes shortest compression and expansion Strokes |
| Answer» C. isentropic compression is on a longer stroke and the expansion on a short stroke | |
| 98. |
For an air conditioning plant above 300 ton, which one of the following system would normally he preferred? |
| A. | Ammonia reciprocating compressor |
| B. | Centrifugal Chiller |
| C. | Absorption refrigeration system |
| D. | Hermetic compressor |
| Answer» B. Centrifugal Chiller | |
| 99. |
The sense of coriolis component 2 vw is the same as that of the relative velocity vector v rotated: |
| A. | \[45{}^\circ \] In the direction of rotation of the link containing the path |
| B. | \[45{}^\circ \] In the direction opposite to the rotation of the link containing the path |
| C. | \[90{}^\circ \] In the direction of rotation of the link containing the path |
| D. | \[180{}^\circ \] In the direction opposite to the rotation of the link containing the path |
| Answer» D. \[180{}^\circ \] In the direction opposite to the rotation of the link containing the path | |
| 100. |
Which of the following symptoms show that the combustion in air is necessarily complete: |
| A. | Absence of oxygen in exhaust |
| B. | Absence of nitrogen in exhaust |
| C. | Absence of free carbon in exhaust |
| D. | Absence of carbon monoxide in exhaust |
| Answer» D. Absence of carbon monoxide in exhaust | |