MCQOPTIONS
Saved Bookmarks
MCQOPTIONS
This section includes 4791 Mcqs, each offering curated multiple-choice questions to sharpen your Engineering knowledge and support exam preparation. Choose a topic below to get started.
| 4651. |
The overall efficiency of an impulse turbine is the ratio of the actual power produced by the turbine to the energy actually supplied by the turbine. |
| A. | Yes |
| B. | No |
| Answer» B. No | |
| 4652. |
In an inward flow reaction turbine |
| A. | the water flows parallel to the axis of the wheel |
| B. | the water enters at the centre of the wheel and then flows towards the outer periphery of the wheel |
| C. | the water enters the wheel at the outer periphery and then flows towards the centre of the wheel |
| D. | the flow of water is partly radial and partly axial |
| Answer» D. the flow of water is partly radial and partly axial | |
| 4653. |
The working of which of the following hydraulic units is based on Pascal's law? |
| A. | Air lift pump |
| B. | Jet pump |
| C. | Hydraulic coupling |
| D. | Hydraulic press |
| Answer» E. | |
| 4654. |
The hydraulic efficiency of a reaction turbine, is the ratio of |
| A. | power produced by the turbine to the energy actually supplied by the turbine |
| B. | actual work available at the turbine to energy imparted to the wheel |
| C. | workdone on the wheel to the energy (or head of water) actually supplied to the turbine |
| D. | none of the above |
| Answer» D. none of the above | |
| 4655. |
In order to avoid cavitation in centrifugal pumps |
| A. | the suction pressure should be high |
| B. | the delivery pressure should be high |
| C. | the suction pressure should be low |
| D. | the delivery pressure should be low |
| Answer» B. the delivery pressure should be high | |
| 4656. |
In a centrifugal pump, the water enters the impeller __________ and leaves the vanes axially. |
| A. | axially |
| B. | radially |
| Answer» C. | |
| 4657. |
A Kaplan turbine is an axial flow reaction turbine. |
| A. | Correct |
| B. | Incorrect |
| Answer» B. Incorrect | |
| 4658. |
A Pelton wheel develops 1750 kW under a head of 100 metres while running at 200 r.p.m. and discharging 2500 litres of water per second. The unit speed of the wheel is |
| A. | 10 r.p.m. |
| B. | 20 r.p.m. |
| C. | 40 r.p.m. |
| D. | 80 r.p.m. |
| Answer» C. 40 r.p.m. | |
| 4659. |
The hydraulic efficiency of an impulse turbine is maximum when velocity of wheel is __________ of the jet velocity, |
| A. | one-fourth |
| B. | one-half |
| C. | three-fourth |
| D. | double |
| Answer» C. three-fourth | |
| 4660. |
Dynamic similarity is said to exist between the model and the prototype, if both of them |
| A. | have identical velocities |
| B. | are equal in size and shape |
| C. | are identical in shape, but differ only in size |
| D. | none of the above |
| Answer» E. | |
| 4661. |
The specific speed of a turbine is given by the equation |
| A. | <img src="/_files/images/mechanical-engineering/hydraulic-machines/197-76-1.png"> |
| B. | <img src="/_files/images/mechanical-engineering/hydraulic-machines/197-76-2.png"> |
| C. | <img src="/_files/images/mechanical-engineering/hydraulic-machines/197-76-3.png"> |
| D. | <img src="/_files/images/mechanical-engineering/hydraulic-machines/197-76-4.png"> |
| Answer» D. <img src="/_files/images/mechanical-engineering/hydraulic-machines/197-76-4.png"> | |
| 4662. |
A draft tube is used with impulse turbines. |
| A. | Yes |
| B. | No |
| Answer» C. | |
| 4663. |
A hydraulic ram is a device used to |
| A. | store the energy of water |
| B. | increase the pressure of water |
| C. | to lift water from deep wells |
| D. | to lift small quantity of water to a greater height when a large quantity of water is available at a smaller height |
| Answer» E. | |
| 4664. |
The cavitation in a hydraulic machine is mainly due to |
| A. | low velocity |
| B. | high velocity |
| C. | low pressure |
| D. | high pressure |
| Answer» D. high pressure | |
| 4665. |
The unit speed of the turbine runner is |
| A. | <img src="/_files/images/mechanical-engineering/hydraulic-machines/197-74-1.png"> |
| B. | <img src="/_files/images/mechanical-engineering/hydraulic-machines/197-74-2.png"> |
| C. | <img src="/_files/images/mechanical-engineering/hydraulic-machines/197-74-3.png"> |
| D. | <img src="/_files/images/mechanical-engineering/hydraulic-machines/197-74-4.png"> |
| Answer» B. <img src="/_files/images/mechanical-engineering/hydraulic-machines/197-74-2.png"> | |
| 4666. |
In a centrifugal pump, the regulating valve is provided on the |
| A. | casing |
| B. | delivery pipe |
| C. | suction pipe |
| D. | impeller |
| Answer» C. suction pipe | |
| 4667. |
A Francis turbine is an outward flow reaction turbine. |
| A. | True |
| B. | False |
| Answer» C. | |
| 4668. |
A jet of water enters and leaves a fixed curved vane tangentially. The force of the jet along normal to the vane is (where and = Inlet and outlet angles of the jet respectively) |
| A. | <img src="/_files/images/mechanical-engineering/hydraulic-machines/191-5-1.png"> |
| B. | <img src="/_files/images/mechanical-engineering/hydraulic-machines/191-5-2.png"> |
| C. | <img src="/_files/images/mechanical-engineering/hydraulic-machines/191-5-3.png"> |
| D. | <img src="/_files/images/mechanical-engineering/hydraulic-machines/191-5-4.png"> |
| Answer» B. <img src="/_files/images/mechanical-engineering/hydraulic-machines/191-5-2.png"> | |
| 4669. |
The specific speed of a hydraulic turbine depends upon |
| A. | speed and power developed |
| B. | discharge and power developed |
| C. | speed and head of water |
| D. | speed, power developed and head of water |
| Answer» E. | |
| 4670. |
A Pelton wheel is |
| A. | tangential flow impulse turbine |
| B. | inward flow impulse turbine |
| C. | outward flow impulse turbine |
| D. | inward flow reaction turbine |
| Answer» B. inward flow impulse turbine | |
| 4671. |
If V1 and V2 are the velocities of water at inlet and outlet of the draft tube respectively, then the efficiency of a draft tube is |
| A. | <img src="/_files/images/mechanical-engineering/hydraulic-machines/195-46-1.png"> |
| B. | <img src="/_files/images/mechanical-engineering/hydraulic-machines/195-46-2.png"> |
| C. | <img src="/_files/images/mechanical-engineering/hydraulic-machines/195-46-3.png"> |
| D. | <img src="/_files/images/mechanical-engineering/hydraulic-machines/195-46-4.png"> |
| Answer» C. <img src="/_files/images/mechanical-engineering/hydraulic-machines/195-46-3.png"> | |
| 4672. |
A jet of water enters and leaves a fixed curved vane tangentially. The force of jet along perpendicular to the vane is zero. |
| A. | True |
| B. | False |
| Answer» C. | |
| 4673. |
The efficiency of jet propulsion for a ship with inlet orifices at right angles to the direction of motion of ship, will be maximum when the relative velocity of the jet and ship is equal to twice the velocity of the ship. |
| A. | Yes |
| B. | No |
| Answer» B. No | |
| 4674. |
The cavitation in reaction turbines is avoided, to a great extent by |
| A. | installing the turbine below the tail race level |
| B. | using stainless steel runner of the turbine |
| C. | providing highly polished blades to the runner |
| D. | all of the above |
| Answer» E. | |
| 4675. |
Which type of the pump is different from others in the same group? |
| A. | Screw pump |
| B. | Gear pump |
| C. | Cam and piston pump |
| D. | Plunger pump |
| Answer» E. | |
| 4676. |
In an axial flow reaction turbine, the water flows __________ to the axis of the wheel. |
| A. | parallel |
| B. | perpendicular |
| Answer» B. perpendicular | |
| 4677. |
The air vessel, in a reciprocating pump, is a cast iron closed chamber having an opening at its base. |
| A. | Agree |
| B. | Disagree |
| Answer» B. Disagree | |
| 4678. |
A double overhung Pelton wheel has |
| A. | two jets |
| B. | two runners |
| C. | four jets |
| D. | four runners |
| Answer» C. four jets | |
| 4679. |
An impulse turbine as compared to a reaction turbine, for a given power has __________ row of blades. |
| A. | equal |
| B. | less |
| C. | more |
| Answer» D. | |
| 4680. |
The effect of bleeding is that |
| A. | it increases the thermodynamic efficiency of the turbine |
| B. | boiler is supplied with hot water |
| C. | it decreases the power developed by the turbine |
| D. | all of the above |
| Answer» E. | |
| 4681. |
The expansion of steam, as it flows over the blades in reaction turbine, represents |
| A. | isothermal process |
| B. | isentropic process |
| C. | throttling process |
| D. | free-expansion process |
| Answer» C. throttling process | |
| 4682. |
The critical pressure ratio for initially superheated steam is __________ as compared to initially dry saturated steam. |
| A. | more |
| B. | less |
| Answer» C. | |
| 4683. |
The flow ratio of Francis turbine is defined as the ratio of the |
| A. | velocity of flow at inlet to the theoretical jet velocity |
| B. | theoretical velocity of jet to the velocity of flow at inlet |
| C. | velocity of runner at inlet to the velocity of flow at inlet |
| D. | none of the above |
| Answer» B. theoretical velocity of jet to the velocity of flow at inlet | |
| 4684. |
The impeller of a centrifugal pump may have |
| A. | volute casing |
| B. | volute casing with guide blades |
| C. | vortex casing |
| D. | any one of these |
| Answer» E. | |
| 4685. |
Kinematic similarity is said to exist between the model and the prototype, if both of them |
| A. | have identical velocities |
| B. | are equal in size and shape |
| C. | are identical in shape, but differ only in size |
| D. | have identical forces |
| Answer» B. are equal in size and shape | |
| 4686. |
Power required (in watts) to drive a centrifugal pump is (where Hm = Manometric head in metres, w = Specific weight in N/m3, Q = Discharge of the pump in m3/s, and o = Overall efficiency of the pump) |
| A. | <img src="/_files/images/mechanical-engineering/hydraulic-machines/200-113-1.png"> |
| B. | <img src="/_files/images/mechanical-engineering/hydraulic-machines/200-113-2.png"> |
| C. | <img src="/_files/images/mechanical-engineering/hydraulic-machines/200-113-3.png"> |
| D. | <img src="/_files/images/mechanical-engineering/hydraulic-machines/200-113-4.png"> |
| Answer» C. <img src="/_files/images/mechanical-engineering/hydraulic-machines/200-113-3.png"> | |
| 4687. |
A reciprocating pump is suitable for less discharge and higher heads. |
| A. | True |
| B. | False |
| Answer» B. False | |
| 4688. |
Manometric head is the actual head of water against which a centrifugal pump has to work. |
| A. | Correct |
| B. | Incorrect |
| Answer» B. Incorrect | |
| 4689. |
The type of centrifugal pump preferred for a specific speed of 20 r.p.m. is |
| A. | slow speed pump with radial flow at outlet |
| B. | medium speed pump with radial flow at outlet |
| C. | high speed pump with radial flow at outlet |
| D. | high speed pump with axial flow at outlet |
| Answer» B. medium speed pump with radial flow at outlet | |
| 4690. |
The power of a centrifugal pump working under constant head and discharge increases with the speed. |
| A. | True |
| B. | False |
| Answer» B. False | |
| 4691. |
The blade friction in the impulse turbine reduces the velocity of steam by __________ while it passes over the blades. |
| A. | 10 to 15% |
| B. | 15 to 20% |
| C. | 20 to 30% |
| D. | 30 to 40% |
| Answer» B. 15 to 20% | |
| 4692. |
The friction present between the steam and the nozzle surfaces reduces the heat drop by |
| A. | 10 to 15 percent |
| B. | 15 to 25 percent |
| C. | 25 to 40 percent |
| D. | 40 to 60 percent |
| Answer» B. 15 to 25 percent | |
| 4693. |
The action of steam in a steam turbine is |
| A. | static |
| B. | dynamic |
| C. | static and dynamic |
| D. | neither static nor dynamic |
| Answer» C. static and dynamic | |
| 4694. |
De-Laval turbine is a |
| A. | single rotor impulse turbine |
| B. | multi-rotor impulse turbine |
| C. | impulse reaction turbine |
| D. | none of these |
| Answer» B. multi-rotor impulse turbine | |
| 4695. |
In a De-Laval nozzle expanding superheated steam from 10 bar to 0.1 bar, the pressure at the minimum cross-section (i. e. pressure at throat, p2) will be |
| A. | 3.3 bar |
| B. | 5.46 bar |
| C. | 8.2 bar |
| D. | 9.9 bar |
| Answer» C. 8.2 bar | |
| 4696. |
Steam turbines are used for |
| A. | large marine propulsion |
| B. | electric power generation |
| C. | direct drive of fans, compressors, pumps |
| D. | all of these |
| Answer» E. | |
| 4697. |
The steam enters the nozzle at a |
| A. | high pressure and a low velocity |
| B. | high pressure and a high velocity |
| C. | low pressure and a low velocity |
| D. | low pressure and a high velocity |
| Answer» B. high pressure and a high velocity | |
| 4698. |
The flow of steam is super-sonic |
| A. | at the entrance to the nozzle |
| B. | at the throat of the nozzle |
| C. | in the convergent portion of the nozzle |
| D. | in the divergent portion of the nozzle |
| Answer» E. | |
| 4699. |
Galvanising is a |
| A. | zinc diffusion process |
| B. | process of coating zinc by hot dipping |
| C. | process used for making thin phosphate coating on steel |
| D. | none of the above |
| Answer» C. process used for making thin phosphate coating on steel | |
| 4700. |
The machining allowance provided on patterns depends upon |
| A. | type of casting metal |
| B. | size and shape of casting |
| C. | method of casting used |
| D. | all of these |
| Answer» E. | |