MCQOPTIONS
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MCQOPTIONS
This section includes 2158 Mcqs, each offering curated multiple-choice questions to sharpen your GATE (Mechanical Engineering) knowledge and support exam preparation. Choose a topic below to get started.
| 1. |
In which of the following methods, the observer concentrates on a point in the fluid system? |
| A. | Langrangian method |
| B. | Eulerian method |
| C. | Any of the above |
| D. | None of the above. |
| Answer» E. | |
| 2. |
In case of a closed cylindrical vessel sealed at the top and the bottom the volume of air before rotation is ...... the volume of air after: |
| A. | More than |
| B. | Less than |
| C. | Equal to |
| D. | None of the above |
| Answer» D. None of the above | |
| 3. |
Regarding cavitation which of the following statements in incorrect? |
| A. | Cavitation affects the performance of a turbine to a lesser degree than that of a pump. |
| B. | Thoma’s cavitation parameter has different expressions for turbines and pumps. |
| C. | With the increase in pump speed, there is increase in its minimum net positive suction head requirement. |
| D. | The leading edge of blades in pumps and the trailing edge of blades in water turbines are more susceptible to cavitation damage |
| Answer» C. With the increase in pump speed, there is increase in its minimum net positive suction head requirement. | |
| 4. |
High velocity flow in a conduit of large size is known as |
| A. | Laminar flow |
| B. | Turbulent flow |
| C. | Either of the above |
| D. | None of the above. |
| Answer» C. Either of the above | |
| 5. |
The tendency for an immersed body to be lifted up in the fluid, due to an upward force opposite to theaction of gravity is known as |
| A. | Buoyancy |
| B. | Centre of buoyancy |
| C. | Buoyant force |
| D. | None of the above. |
| Answer» B. Centre of buoyancy | |
| 6. |
........ is defined as a scalar function of space and time such that its negative derivative with respect to any direction gives the fluid velocity in that direction. |
| A. | Velocity potential function |
| B. | Stream function |
| C. | Circulation |
| D. | Vorticity. |
| Answer» B. Stream function | |
| 7. |
The pressure gradient in the direction of flow is equal to the shear gradient in the direction |
| A. | Parallel to the direction of flow |
| B. | Normal to the direction of flow |
| C. | Either of the above |
| D. | None of the above. |
| Answer» C. Either of the above | |
| 8. |
Specific speed of a turbo-machine |
| A. | Relates the shape rather than the size of the machine |
| B. | Remains unchanged under different condi tions of operation |
| C. | Has the dimensions of rotational speed |
| D. | Is the speed of a machine having unit dimensions. |
| Answer» B. Remains unchanged under different condi tions of operation | |
| 9. |
The total energy represented by the Bernoulli’s equation (p/ρg +V2/2g +z) has the units: |
| A. | Nm/s |
| B. | Ns/m |
| C. | Nm/m |
| D. | Nm/N. |
| Answer» E. | |
| 10. |
Compressibility is the reciprocal of |
| A. | Bulk modulus of elasticity |
| B. | Shear modulus of elasticity |
| C. | Young’s modulus of elasticity |
| D. | Any of the above. |
| Answer» B. Shear modulus of elasticity | |
| 11. |
Darcy-Weisbach equation is used to find loss of head due to : |
| A. | Sudden enlargement |
| B. | Sudden contraction |
| C. | Friction |
| D. | None of the above. |
| Answer» D. None of the above. | |
| 12. |
Flow in a pipe where average flow parameters are considered for analysis is an example of |
| A. | Incompressible flow |
| B. | One-dimensional flow |
| C. | Two-dimensional flow |
| D. | Three-dimensional flow. |
| Answer» C. Two-dimensional flow | |
| 13. |
The term........ means the study of pressure exerted by a fluid at rest. |
| A. | Hydrostatics |
| B. | Fluid mechanics |
| C. | Continuum |
| D. | Kinetics |
| Answer» B. Fluid mechanics | |
| 14. |
The value of speed ratio (Ku) in case of a Francis turbine ranges from |
| A. | 0.2 to 0.3 |
| B. | 0.4 to 0.5 |
| C. | 0.6 to 0.9 |
| D. | None of the above. |
| Answer» D. None of the above. | |
| 15. |
The effective (or net) head at the turbine is |
| A. | The sum of gross head plus head loss in penstock and the velocity head at the turbine exit. |
| B. | The difference between gross head minus the head loss in penstock |
| C. | The difference between the gross head minus head loss in penstock and the velocity head at the turbine exit |
| D. | The sum of gross head plus the head loss in the penstock. |
| Answer» D. The sum of gross head plus the head loss in the penstock. | |
| 16. |
If velocity potential (φ) satisfies the Laplace equation, it represents the possible..... flow. |
| A. | Unsteady, compressible, rotational |
| B. | Steady, compressible, irrotational |
| C. | Unsteady, incompressible, rotational |
| D. | Steady, incompressible, irrotational. |
| Answer» E. | |
| 17. |
The delivery valve, while starting centrifugal pump, is kept |
| A. | Fully closed |
| B. | Fully open |
| C. | Half open |
| D. | In any position. |
| Answer» B. Fully open | |
| 18. |
Which of the following statements is correct with reference to an impeller with backward curved vanes? |
| A. | It has a falling head - discharge characteristic. |
| B. | It has rising head - discharge characteristic |
| C. | It is easier to fabricate. |
| D. | It cannot run at speeds other than the design speed. |
| Answer» B. It has rising head - discharge characteristic | |
| 19. |
A centrifugal pump should be so installed above the water level in the sump such that |
| A. | The negative pressures are not allowed to develop in the impeller |
| B. | The negative pressures do not reach as low a value as the vapour pressure |
| C. | Its height is more than 10·28 m at ordinary temperature of liquid |
| D. | None of the above. |
| Answer» C. Its height is more than 10·28 m at ordinary temperature of liquid | |
| 20. |
Which of the following types of impeller is used for centrifugal pumps dealing with muds? |
| A. | One-side shrouded |
| B. | Two -sides shrouded |
| C. | Double section |
| D. | Open. |
| Answer» E. | |
| 21. |
In a pipe flow the minor losses are those |
| A. | Which depend on the length of the pipeline |
| B. | Caused by friction and are thus also called friction losses. |
| C. | Which have a small magnitude |
| D. | Which are caused on account of total disturbance produced by such fittings as valves, bends, etc. |
| Answer» E. | |
| 22. |
For turbulent flow in smooth pipes, the entrance length is taken as |
| A. | 20 |
| B. | 50 |
| C. | 80 |
| D. | 115. |
| Answer» C. 80 | |
| 23. |
The branch of Engineering-science, which deals with water at rest or in motion is called |
| A. | hydraulics |
| B. | Fluid mechanics |
| C. | Applied mechanics |
| D. | Kinematics. |
| Answer» B. Fluid mechanics | |
| 24. |
When a Pitot-tube is put to use it must be ensured that its alignment is such that: |
| A. | The horizontal leg should be inclined at 45° in plan |
| B. | Its horizontal leg is at right angles to the flow direction |
| C. | Its opening faces upstream and the horizontal leg is perfectly aligned with the direction of flow |
| D. | None of the above. |
| Answer» D. None of the above. | |
| 25. |
Which of the following is an advantage of dimensional analysis? |
| A. | It expresses the functional relationship between the variables in dimensionless terms |
| B. | In hydraulic model studies it reduces the number of variables involved in a physical phenomenon, generally by three |
| C. | By the use of dimensional analysis design curves can be developed from experimental data or direct solution of the problem |
| D. | All of the above. |
| Answer» E. | |
| 26. |
The maximum velocity in a circular pipe when flow is laminar occurs at |
| A. | The top of the pipe |
| B. | The bottom of the pipe |
| C. | The centre of the pipe |
| D. | Not necessarily at the centre. |
| Answer» D. Not necessarily at the centre. | |
| 27. |
The change in moment of momentum of fluid due to flow along a curved path results in: |
| A. | A change in pressure |
| B. | Torque |
| C. | A change in the total energy |
| D. | None of the above. |
| Answer» C. A change in the total energy | |
| 28. |
The runner passages of a reaction turbine are |
| A. | Partially filled with water |
| B. | Always completely filled with water |
| C. | Never filled with water |
| D. | None of the above. |
| Answer» C. Never filled with water | |
| 29. |
Which of the following serious problems arise from cavitation? |
| A. | Noise and vibration. |
| B. | Damage to blade surface. |
| C. | Fall in efficiency. |
| D. | All of the above. |
| Answer» E. | |
| 30. |
Higher specific speeds (160 to 500) of centrifugal pump indicate that the pump is of |
| A. | Radial flow type |
| B. | Axial flow type |
| C. | Mixed flow type |
| D. | Any of these types. |
| Answer» C. Mixed flow type | |
| 31. |
Which of the following devices is used to store energy of liquid under pressure and make this energy available to hydraulic machines? |
| A. | Hydraulic coupling |
| B. | Hydraulic accumulator |
| C. | Hydraulic ram |
| D. | Hydraulic press. |
| Answer» C. Hydraulic ram | |
| 32. |
In a steady flow the velocity |
| A. | Does not change from place to place |
| B. | At a given point does not change with time |
| C. | May change its direction but the magnitude remains unchanged |
| D. | None of the above. |
| Answer» C. May change its direction but the magnitude remains unchanged | |
| 33. |
The scale effect in models can be |
| A. | Positive only |
| B. | Negative only |
| C. | Both positive and negative |
| D. | None of the above. |
| Answer» D. None of the above. | |
| 34. |
Which of the following statements pertaining to a given centrifugal pump is correct? |
| A. | Discharge varies as the square of speed |
| B. | Power varies as the square of speed |
| C. | Discharge varies directly as speed |
| D. | Head varies inversely as speed. |
| Answer» D. Head varies inversely as speed. | |
| 35. |
The ratio of power developed by the runner to the power supplied by the jet at entrance to the turbine isknown as |
| A. | Hydraulic efficiency |
| B. | Mechanical efficiency |
| C. | Volumetric efficiency |
| D. | Overall efficiency. |
| Answer» B. Mechanical efficiency | |
| 36. |
The co-efficient of discharge of an orificemeter is ......that of a venturimeter. |
| A. | Equal to |
| B. | Much smaller than |
| C. | Much more than |
| D. | Any of these. |
| Answer» C. Much more than | |
| 37. |
Which of the following surge tank is also called a throttled surge tank? |
| A. | Inclined surge tank. |
| B. | Expansion chamber surge tank. |
| C. | Restricted orifice surge tank. |
| D. | None of the above |
| Answer» D. None of the above | |
| 38. |
Which of the following turbines is least efficient under part load conditions: |
| A. | Propeller |
| B. | Kaplan |
| C. | Francis |
| D. | Pelton. |
| Answer» B. Kaplan | |
| 39. |
The function of which of the following hydraulic devices is analogous to that of the flywheel of a reciprocating engine and an electric storage battery? |
| A. | Hydraulic ram |
| B. | Hydraulic accumulator |
| C. | Hydraulic intensifier |
| D. | Hydraulic coupling. |
| Answer» C. Hydraulic intensifier | |
| 40. |
Dimensional analysis is used to |
| A. | Test the dimensional homogeneity of any equation of fluid motion |
| B. | Derive rational formulae for a flow phenomenon |
| C. | Derive equations expressed in terms of non– dimensional parameters |
| D. | All of the above. |
| Answer» E. | |
| 41. |
Which of the following statements is a definition of the hydraulic efficiency of a turbine? |
| A. | The ratio of power available at the turbine shaft to that supplied to it by runner. |
| B. | The ratio of the power supplied by the runner to the power available at the shaft. |
| C. | The ratio of power utilized by runner to that supplied by the water at entry to the turbine. |
| D. | The ratio of power supplied by water at entry to the power utilized by runner. |
| Answer» D. The ratio of power supplied by water at entry to the power utilized by runner. | |
| 42. |
In case of forced vortex, the rise of liquid level at the ends is .... the fall of liquid level at the axis of rotation. |
| A. | Less than |
| B. | More than |
| C. | Equal to |
| D. | None of the above |
| Answer» D. None of the above | |
| 43. |
The flow is said to be turbulent when Reynolds number is |
| A. | Less than 1000 |
| B. | Equal to 2000 |
| C. | Greater than 4000 |
| D. | Between 1000 to 4000. |
| Answer» D. Between 1000 to 4000. | |
| 44. |
Any pressure measured above the absolute zero of pressure is termed as |
| A. | Atmospheric pressure |
| B. | Gauge pressure |
| C. | Either of the above |
| D. | None of the above |
| Answer» D. None of the above | |
| 45. |
The K.E. correction factor a for a circular pipe is equal to |
| A. | 2 |
| B. | 3 |
| C. | 4 |
| D. | 6. |
| Answer» B. 3 | |
| 46. |
Which of the following draft tubes is suited particularly for helical flow? |
| A. | Conical type draft tube. |
| B. | Elbow type draft tube. |
| C. | Moody’s spreading draft tube. |
| D. | None of the above. |
| Answer» D. None of the above. | |
| 47. |
The efficiency of jet propulsion with inlet orifices at right angles to the direction of motion of ship isgiven by |
| A. | 2u/ (V + u) |
| B. | 2V/ (V + u) 2 |
| C. | 2Vu/ (V + u) 2 |
| D. | 2u (V-u)/V3 |
| Answer» C. 2Vu/ (V + u) 2 | |
| 48. |
Under which of the following conditions the closure of valve is considered rapid? (where L = length of pipe, C = velocity of pressure wave produced due to water hammer.) |
| A. | The duration of valve closure is greater than 2L/C |
| B. | The duration of valve closure is less than L/C |
| C. | The duration of valve closure is less than 2L/C |
| D. | None of the above. |
| Answer» D. None of the above. | |
| 49. |
A flow net is a graphical representation of strea lines and equipotential lines such that these lines |
| A. | Intersect each other orthogonally forming curvilinear squares |
| B. | Intersect each other at various different angles forming irregular-shaped nets |
| C. | Indicate the direction and magnitude of vector |
| D. | None of the above. |
| Answer» B. Intersect each other at various different angles forming irregular-shaped nets | |
| 50. |
Normal acceleration in fluid-flow situation exists only when |
| A. | The flow is unsteady |
| B. | The flow is two-dimensional |
| C. | The streamlines are straight and parallel |
| D. | The streamlines are curved. |
| Answer» C. The streamlines are straight and parallel | |