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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.
| 251. |
The speed ratio of an impulse turbine operating under a head off 400m is 0.46. The p.c.d ofturbine wheel is 22.25m then rotational speed, in rpm is |
| A. | 245 |
| B. | 346 |
| C. | 692 |
| D. | 946 |
| Answer» C. 692 | |
| 252. |
A turbine works at 20 m head and speed of 500 rpm. Its 1:2 scale model to be tested at samehead should have a rotational speed of |
| A. | 1000rpm |
| B. | 750rpm |
| C. | 500rpm |
| D. | 250rpm |
| Answer» E. | |
| 253. |
To generate 8.1 MW under a head of 81m while working at a speed of 540rpm, what type ofturbine is suitable? |
| A. | pelton wheel |
| B. | francis turbine |
| C. | kaplan turbine |
| D. | propeller turbine |
| Answer» C. kaplan turbine | |
| 254. |
A reaction turbine discharges 50m3/sec of water under a head of 7.5m with an overall efficiencyof 80%. The H.P. Developed is: |
| A. | 5000 |
| B. | 300 |
| C. | 4000 |
| D. | 400 |
| Answer» D. 400 | |
| 255. |
A turbine develops 3417hp at 240 r.p.m. The torque in the shaft is |
| A. | 400kn.m |
| B. | 3335kn.m |
| C. | 1000kn.m |
| D. | 100kn.m |
| Answer» E. | |
| 256. |
A draft tube is a part of the installation of a |
| A. | propeller turbine |
| B. | pelton turbine |
| C. | turbine impulse wheel |
| D. | all the turbines |
| Answer» B. pelton turbine | |
| 257. |
The function of draft tube is |
| A. | recuperation of energy |
| B. | to make it possible to establish the turbine above tail race |
| C. | both (a) and (b) |
| D. | none |
| Answer» D. none | |
| 258. |
The reaction turbine is one in which the available hydraulic energy is converted to kinetic energybefore the fluid enters the runner |
| A. | fully |
| B. | partially |
| C. | fully or partially |
| D. | fully and partially |
| Answer» C. fully or partially | |
| 259. |
A Pelton turbine is |
| A. | an impulse turbine |
| B. | a tangential flow |
| C. | high had and low specific speed turbine |
| D. | all of the above |
| Answer» E. | |
| 260. |
An impulse turbine is installed |
| A. | always above the tail race |
| B. | always submerged |
| C. | depends on flow situation |
| D. | partly submerged |
| Answer» B. always submerged | |
| 261. |
An impulse turbine: |
| A. | is always operates submerged |
| B. | is makes use of draft tube |
| C. | is most suited for low head installation |
| D. | operates by initial complete conversion to kinetic head |
| Answer» E. | |
| 262. |
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 | |
| 263. |
For a given discharge in a horizontal frictionless channel two depths may have the same specificforce. These two depths are known as… |
| A. | sudden depth |
| B. | conjugate depths |
| C. | sequent depths |
| D. | normal and critical depths |
| Answer» D. normal and critical depths | |
| 264. |
In a horizontal rectangular channel a hydraulic jump with a sequent depth ratio of 5.0 is formed. Thisjump can be classified as |
| A. | weak jump |
| B. | oscillating jump |
| C. | strong jump |
| D. | steady jump |
| Answer» C. strong jump | |
| 265. |
The hydraulic jump always occurs from |
| A. | a m2 curve to a m1 curve |
| B. | a h3 curve to a h1 curve |
| C. | below normal depth to above normal depth |
| D. | below critical depth to above critical depth |
| Answer» E. | |
| 266. |
A hydraulic jump occurs at the top of a spillway. The depth before jump is 0.2m. The sequent depthis 3.2m. What is the energy dissipated in m (approximate)? |
| A. | 27 |
| B. | 10.5 |
| C. | 15 |
| D. | 42 |
| Answer» C. 15 | |
| 267. |
A hydraulic jump takes place in a horizontal rectangular channel from a depth of 0.20m to 2.40m Thedischarge in the channel in m3/s per meter width is… |
| A. | 2.47 |
| B. | 12.0 |
| C. | 3.2 |
| D. | 0.08 |
| Answer» B. 12.0 | |
| 268. |
al to 2m and 1m respectively. If the flow is uniform and the value of Chezy’s constant is 60, thedischarge through the channel is |
| A. | 1.0 m3/s |
| B. | 1.5m3/s |
| C. | 2.0m3/s |
| D. | 3.0m3/s |
| Answer» C. 2.0m3/s | |
| 269. |
A hydraulically efficient trapezoidal section has a side slopes of 2 horizontal :1 vertical. The ratio ofthe bed width to depth B/y in this channel is |
| A. | 4.94 |
| B. | 2.19 |
| C. | 0.472 |
| D. | 0.236 |
| Answer» D. 0.236 | |
| 270. |
The most economical section is one for which a given cross sectional area, the slope of the bed (s)and coefficient of resistance has |
| A. | maximum wetted perimeter |
| B. | maximum discharge |
| C. | maximum depth of flow |
| D. | none of the above |
| Answer» C. maximum depth of flow | |
| 271. |
The maximum discharge through a circular channel takes place when depth of flow is equal to |
| A. | 0.95 x diameter |
| B. | 0.3 x diameter |
| C. | 0.81 x diameter |
| D. | 0.5 x diameter |
| Answer» B. 0.3 x diameter | |
| 272. |
The maximum velocity through a circular channel when depth flow is equal to |
| A. | 0.95 x diameter |
| B. | 0.5 x diameter |
| C. | 0.81 x diameter |
| D. | none of the above |
| Answer» D. none of the above | |
| 273. |
The discharge through the trapezoidal channel is maximum when |
| A. | half of the top width= sloping side |
| B. | top width= half of the sloping side |
| C. | top width= 1.5 x sloping side |
| D. | none of the above |
| Answer» B. top width= half of the sloping side | |
| 274. |
Chezy’s Formula is given as |
| A. | v= s√(rc) |
| B. | v= c √(rs) |
| C. | v= r √(cs) |
| D. | none of the above. |
| Answer» C. v= r √(cs) | |
| 275. |
If the density of the flow changes from point to point in a flow region, it is called |
| A. | steady flow. |
| B. | unsteady flow |
| C. | non uniform |
| D. | compressible |
| Answer» E. | |
| 276. |
If the density of the fluid is constant from point to point in a flow region, it is called |
| A. | steady flow. |
| B. | incompressible flow |
| C. | uniform flow |
| D. | rotational flow. |
| Answer» C. uniform flow | |
| 277. |
If the velocity in a fluid flow change with respect to length of direction of flow, it is called |
| A. | unsteady flow |
| B. | compressible flow |
| C. | irrotational flow |
| D. | none of the above |
| Answer» E. | |
| 278. |
If the velocity in a fluid flow does not change with respect to length of direction of flow, it is called |
| A. | steady flow |
| B. | uniform flow |
| C. | incompressible |
| D. | rotational |
| Answer» C. incompressible | |
| 279. |
If velocity, pressure, density etc., change at a point with respect to time, flow is called |
| A. | uniform |
| B. | compressible |
| C. | unsteady |
| D. | incompressible |
| Answer» D. incompressible | |
| 280. |
If Velocity, pressure, density etc., do not change at a point with respect to time, flow is called |
| A. | uniform |
| B. | incompressible |
| C. | non-uniform |
| D. | steady |
| Answer» E. | |
| 281. |
The desired hydraulic efficiency of a Kaplan turbine is 98% at a whirl velocity of 20 m/s and a head of 60 m. What should be the blade velocity of the turbine at inlet in m/s? Take g = 10 m/s2. |
| A. | 40 |
| B. | 60 |
| C. | 80 |
| D. | 30 |
| Answer» E. | |
| 282. |
Gauge pressure at a point is equal to the absolute pressure __________ the atmosphericpressure. |
| A. | Plus |
| B. | Minus |
| C. | Divide |
| D. | Multiply |
| Answer» C. Divide | |
| 283. |
The exit diameter for a simple elbow draft tube should be |
| A. | Large |
| B. | Small |
| C. | Very small |
| D. | Same |
| Answer» B. Small | |
| 284. |
Different velocities in a centrifugal pump are determined by using |
| A. | Velocity triangle |
| B. | Reynolds number |
| C. | Froude number |
| D. | Overall efficiency View Answer |
| Answer» B. Reynolds number | |
| 285. |
Which type of turbine is a Francis Turbine? |
| A. | Impulse Turbine |
| B. | Screw Turbine |
| C. | Reaction turbine |
| D. | Turgo turbine |
| Answer» D. Turgo turbine | |
| 286. |
When the NPSH is low, it leads to |
| A. | Breaking |
| B. | Wear |
| C. | Corrosion |
| D. | Cavitation View Answer |
| Answer» E. | |
| 287. |
Work done per second by a Francis turbine can be given by ρAVf (Vw1u1 + Vw2u2). |
| A. | True |
| B. | False |
| C. | none |
| D. | none |
| Answer» C. none | |
| 288. |
Which among the following is formula for force when it acts along the direction of flow? |
| A. | pav2Sin2θ |
| B. | pav Sin2θ |
| C. | pa Sin2θ |
| D. | maE Sin2θ |
| Answer» B. pav Sin2θ | |
| 289. |
In outward radial flow reaction turbine the ratio of tangential wheel at inlet to given velocity of jet is known as |
| A. | Speed ratio |
| B. | Flow ratio |
| C. | Discharge |
| D. | Radial discharge |
| Answer» C. Discharge | |
| 290. |
Magnetic coupled pumps are also called as |
| A. | Series pumps |
| B. | Parallel pumps |
| C. | Froth pumps |
| D. | Drive pumps View Answer |
| Answer» E. | |
| 291. |
The output that we get after an internal breakage can be classed as |
| A. | An increase |
| B. | A decrease |
| C. | Constant |
| D. | An independent variable View Answer |
| Answer» D. An independent variable View Answer | |
| 292. |
In an inward flow reaction turbine the discharge |
| A. | Increases |
| B. | Decreases |
| C. | Same |
| D. | Independent |
| Answer» C. Same | |
| 293. |
A liquid flows through pipes 1 and 2 with the same flow velocity. If the ratio of their pipe diameters d1 : d2 be 3:2, what will be the ratio of the head loss in the two pipes? |
| A. | 3:2 |
| B. | 9:4 |
| C. | 2:3 |
| D. | 4:9 View Answer |
| Answer» D. 4:9 View Answer | |
| 294. |
An outward radial reaction turbine has |
| A. | u1 < u2 |
| B. | u1 > u2 |
| C. | u1 = u2 |
| D. | u2 = u1 = 0 |
| Answer» B. u1 > u2 | |
| 295. |
In outward flow reaction turbine tangential velocity at inlet is always_ than outlet velocity. |
| A. | Equal |
| B. | Less |
| C. | More |
| D. | Constant |
| Answer» C. More | |
| 296. |
According to Newton's law of viscosity, the shear stress on a layer of a fluid is __________ tothe rate of shear strain. |
| A. | Equal to |
| B. | Directly proportional |
| C. | Inversely proportional |
| D. | None of these |
| Answer» C. Inversely proportional | |
| 297. |
The turbine does not have to be at the lowest point of water flow as long as the water in the draft tube is full. |
| A. | True |
| B. | False |
| C. | none |
| D. | none |
| Answer» B. False | |
| 298. |
10.The expression for water power in Pelton wheel is |
| A. | (P*g*Q*H) Kw |
| B. | (g*Q*H*a) Kw |
| C. | (g*Q) Kw |
| D. | (g*H) Kw |
| Answer» B. (g*Q*H*a) Kw | |
| 299. |
The speed of the turbine in a constant head curve is varied by |
| A. | Temperature change |
| B. | Reaction speed change |
| C. | Changing the gate opening |
| D. | Wheel speed change |
| Answer» D. Wheel speed change | |
| 300. |
Drag force is affected by__________ |
| A. | Cross sectional area and smoothness |
| B. | Rigidity and density |
| C. | Pressure and temperature |
| D. | Mass |
| Answer» B. Rigidity and density | |