MCQOPTIONS
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MCQOPTIONS
This section includes 238 Mcqs, each offering curated multiple-choice questions to sharpen your Fluid Mechanics knowledge and support exam preparation. Choose a topic below to get started.
| 201. |
A turbine in which steam expands both in nozzle as well as in blades is called as |
| A. | impulse reaction turbine |
| B. | reciprocating steam turbine |
| C. | gas turbine |
| D. | Curtis turbine |
| Answer» B. reciprocating steam turbine | |
| 202. |
As water flows through the runner of a reaction turbine, the pressure acting on it would vary from: |
| A. | atmospheric pressure to vacuum |
| B. | more than atmospheric pressure to vacuum |
| C. | less than atmospheric pressure to zero gauge pressure |
| D. | atmospheric pressure to more than atmospheric pressure |
| Answer» C. less than atmospheric pressure to zero gauge pressure | |
| 203. |
A centrifugal pump runs at the speed of 1450 rpm and discharges 0.118 m3/s of water. The pump works against the head of 25 m. The impeller radius is 12.5 cm, its width at the outlet is 5 cm and manometric efficiency is 75%. The vane angle in degrees at the outer periphery of the impeller is:. |
| A. | 79.77 |
| B. | 39.77 |
| C. | 49.77 |
| D. | 59.77 |
| Answer» E. | |
| 204. |
A draft tube helps in converting kinetic energy into |
| A. | thermal energy |
| B. | electrical energy |
| C. | pressure energy |
| D. | chemical energy |
| Answer» D. chemical energy | |
| 205. |
A hydraulic turbine has an output of 6000 kW when it works under a head of 25 m and runs at 100 rm. Then the type of turbine used is |
| A. | Peloton wheel |
| B. | Francis |
| C. | Kaplan |
| D. | Propeller |
| Answer» C. Kaplan | |
| 206. |
In a Francis turbine, the runner blades are radial at the inlet and the discharge leaves the runner radially at the exit. For this turbine |
| A. | The relative velocity is radial at the outlet |
| B. | The absolute velocity is radial at the outlet |
| C. | The guide vane angle is 90° |
| D. | The velocity of flow is constant |
| Answer» C. The guide vane angle is 90° | |
| 207. |
A Kaplan turbine is suitable for- |
| A. | High head low discharge |
| B. | High head high discharge |
| C. | Low head low discharge |
| D. | Low head high discharge |
| Answer» E. | |
| 208. |
In a hydropower plant, the penstock: |
| A. | Conveys water from dam to turbine |
| B. | Is a frictionless pipe |
| C. | Is a component of the governor |
| D. | Serves as a short – term water storage |
| Answer» B. Is a frictionless pipe | |
| 209. |
Kaplan turbine is a propeller turbine in which the vanes fixed on the hub are |
| A. | Non-adjustable |
| B. | Adjustable |
| C. | Fixed |
| D. | None of the above |
| Answer» C. Fixed | |
| 210. |
Cavitation in a centrifugal pump is caused by: |
| A. | Low flow velocity |
| B. | High flow velocity |
| C. | Low pressure |
| D. | High pressure |
| Answer» D. High pressure | |
| 211. |
If the water flow through the runner in radial direction but leaves in the direction parallel to axis of rotation of the runner, the turbine is called: |
| A. | Reaction turbine |
| B. | Mixed flow turbine |
| C. | Inward turbine |
| D. | Radial flow turbine |
| Answer» C. Inward turbine | |
| 212. |
In the inlet part of the jet impinging on a Pelton bucket, the velocity of whirl Vw1 is equal to |
| A. | absolute velocity of jet at intel V1 |
| B. | relative velocity of jet at intel Vr1 |
| C. | zero |
| D. | None of the above |
| Answer» B. relative velocity of jet at intel Vr1 | |
| 213. |
Kaplan turbine is a/an |
| A. | Impulse turbine |
| B. | Radial flow impulse turbine |
| C. | Axial flow reaction turbine |
| D. | Radial flow reaction turbine |
| Answer» D. Radial flow reaction turbine | |
| 214. |
A centrifugal pump is required to lift 0.0125 m3/s of water from a well with depth 30 m. If rating of the pump motor is 5 kW, and the density of water is 1000 kg/m3, the efficiency of the pump will be nearly |
| A. | 82% |
| B. | 74% |
| C. | 66% |
| D. | 58% |
| Answer» C. 66% | |
| 215. |
If γ is the angle subtended by two adjacent buckets in a Pelton wheel then the number of buckets is equal to |
| A. | 40/γ |
| B. | 180/γ |
| C. | 270/γ |
| D. | 360/γ |
| Answer» E. | |
| 216. |
A Pelton wheel operates under a head of 900 m. The speed ratio of the wheel is 0.45. The peripheral speed of the turbine wheel is: |
| A. | 60 m/s |
| B. | 45 m/s |
| C. | 75 m/s |
| D. | 90 m/s |
| Answer» B. 45 m/s | |
| 217. |
______ is the head against which a centrifugal pump has to work |
| A. | Manometric head |
| B. | Suction head |
| C. | Vertical head |
| D. | Delivery head |
| Answer» B. Suction head | |
| 218. |
A centrifugal pump is operating at a flow rate and head given by the intersection of its H-Q curve with the load H-Q curve, near its maximum efficiency point. If water level in the sump, from where water is being pumped, increases, then the operating condition will shift to: |
| A. | Higher head and lower flow rate |
| B. | Higher flow rate and higher head |
| C. | Higher flow rate and lower head |
| D. | Lower head and same flow rate |
| Answer» D. Lower head and same flow rate | |
| 219. |
In all reaction turbines, for maximum efficiency, |
| A. | the velocity of swirl at the entrance must be zero |
| B. | the velocity of flow at outlet must be zero |
| C. | the velocity of swirl at the outlet must be zero |
| D. | the velocity of flow at entrance must be zero |
| E. | temperature of fluid must remain constant |
| Answer» D. the velocity of flow at entrance must be zero | |
| 220. |
In Sardar Sarovar dam, around 80% of the total power is generated using: |
| A. | Francis Turbine |
| B. | Kaplan Turbine |
| C. | Pelton Turbine |
| D. | Gravity Turbine |
| Answer» B. Kaplan Turbine | |
| 221. |
A centrifugal pump acts as a reverse of : |
| A. | outward radial flow reaction turbine |
| B. | pelton turbine |
| C. | inward radial flow reaction turbine |
| D. | reciprocating pump |
| Answer» D. reciprocating pump | |
| 222. |
A centrifugal pump: |
| A. | flow is radially outwards in this pump |
| B. | fluid gain is through constant head |
| C. | flow is tangential in this pump |
| D. | works on the same principle as that of a Francis turbine |
| Answer» B. fluid gain is through constant head | |
| 223. |
Maximum volume flow rate through pump occurs when |
| A. | Net head is maximum |
| B. | Net head is zero |
| C. | Pump operates at best efficiency point |
| D. | Net head is greater than zero but less than maximum |
| Answer» C. Pump operates at best efficiency point | |
| 224. |
Air at 20°C and 105 Pa enters the bottom of an 85° conical flow meter duct at a mass flow rate of 0.3 kg/s, as shown in the figure. It supports the centered conical body by steady annular flow around the cone and exits at the same velocity as it enters. Estimate the weight of the body in Newtons |
| A. | 2.5 N |
| B. | 1 N |
| C. | 3.5 N |
| D. | 4 N |
| Answer» B. 1 N | |
| 225. |
If ϕ is the blade angle at the outlet, then the maximum hydraulic efficiency of an ideal impulse turbine is |
| A. | \(\frac{{1 + \cos \phi }}{2}\) |
| B. | \(\frac{{1 - \cos \phi }}{2}\) |
| C. | \(\frac{{1 - \sin \phi }}{2}\) |
| D. | \(\frac{{1 + \sin \phi }}{2}\) |
| Answer» B. \(\frac{{1 - \cos \phi }}{2}\) | |
| 226. |
An impulse turbine is used for ________. |
| A. | Low head of water |
| B. | High head of water |
| C. | Medium head of water |
| D. | High discharge |
| Answer» C. Medium head of water | |
| 227. |
All reaction turbine will have maximum efficiency if swirl velocity at the outlet will be equal to: |
| A. | zero |
| B. | runner inlet velocity |
| C. | runner outlet velocity |
| D. | inlet swirl velocity |
| Answer» B. runner inlet velocity | |
| 228. |
A double-acting reciprocating pump having piston area 0.1 m2 has a stroke 0.30 m long.The pump is discharging 2.4 m3 of water per minute at 45 rpm through a height of 10 m.The slip of the pump and power required to drive the pump will be nearly |
| A. | 0.005 m3/s and 4.8 kW |
| B. | 0.003 m3/s and 4.8 kW |
| C. | 0.005 m3/s and 4.4 kW |
| D. | 0.003 m3/s and 4.4 kW |
| Answer» D. 0.003 m3/s and 4.4 kW | |
| 229. |
In a reciprocating pump without air vessel, the friction head in the delivery pipe is maximum at the crank angle θ = ? |
| A. | 0° |
| B. | 90° |
| C. | 135° |
| D. | 180° |
| Answer» C. 135° | |
| 230. |
A reciprocating pump has stroke of 30 cm, speed of 100 rpm, and a piston of 22.5 cm diameter. It discharges 18.9 lps. What is the slip of the pump? |
| A. | 3.12% |
| B. | 3.54% |
| C. | 4.15% |
| D. | 4.95% |
| Answer» E. | |
| 231. |
A turbine is a device which converts______ |
| A. | Hydraulic energy into mechanical energy |
| B. | Mechanical energy into hydraulic energy |
| C. | Kinetic energy into mechanical energy |
| D. | Electrical energy into mechanical energy |
| Answer» B. Mechanical energy into hydraulic energy | |
| 232. |
A Kaplan turbine is a |
| A. | Outward flow reaction turbine |
| B. | Inward flow impulse turbine |
| C. | Low head axial flow turbine |
| D. | High head mixed flow turbine |
| Answer» D. High head mixed flow turbine | |
| 233. |
A pump having an efficiency of 68% delivers 3 L/s of water against a head of 22 m. Compute the power requirement of the pump in W |
| A. | 952 |
| B. | 850 |
| C. | 1050 |
| D. | 752 |
| Answer» B. 850 | |
| 234. |
A water jet, 0.0020 m2 in area, is issued from a nozzle with a velocity of 10 m/s. It is made to impinge perpendicular on a plate that moves away from the jet with a velocity of 5 m/s. The force on the plate is: |
| A. | 75 N |
| B. | 100 N |
| C. | 50 N |
| D. | 150 N |
| Answer» D. 150 N | |
| 235. |
A centrifugal pump has an impeller of 30 cm diameter and runs at 1000 rpm giving best efficiency. It delivered 1.2 m3/minute against a head of 25 m. What is its non-dimensional specific speed (based on flow expressed in l.p.s)? Take \(\sqrt {9.81} = 3.132\); and \(\sqrt {\sqrt {9.81} } = 1.77\) |
| A. | 55 |
| B. | 63 |
| C. | 72 |
| D. | 80 |
| Answer» D. 80 | |
| 236. |
A Pelton wheel with single jet rotates at 600 rpm. The velocity of the jet from the nozzle is 100 m/s. If the ratio of the bucket velocity to jet velocity is 0.44 and the speed ratio is 0.43, what is the coefficient of velocity of the nozzle? |
| A. | 0.817 |
| B. | 0.882 |
| C. | 0.975 |
| D. | 0.977 |
| Answer» E. | |
| 237. |
If the manometric efficiency and mechanical efficiency of a centrifugal pump are 70% and 80%, respectively. Determine the overall efficiency of the pump. |
| A. | 0.1 |
| B. | 0.56 |
| C. | 0.53 |
| D. | 0.6 |
| Answer» C. 0.53 | |
| 238. |
A centrifugal pump used for pumping liquids containing suspended solids, such as sewage or pulp from paper mills ______. |
| A. | Has a shrouded impellor |
| B. | Starts without priming |
| C. | Needs to be operated at low rpm |
| D. | Has an open impeller |
| Answer» E. | |