The peripheral velocity at inlet of a centrifugal pump having inlet
diameter of 25 cms and rotating at 950 rpm is __________ m/sec.
(A) 1.8
(B) 12.4
(C) 186.2
(D) 736.4

1 Answer

Answer :

(B) 12.4

Related questions

Description : A threshing cylinder of 15cm radius is rotating at 700rpm if peripheral velocity (m/sec) will be a. 11 b.105 c. 210 d. 660

Last Answer : a. 11

Description : In a slider crank mechanism, the crank is rotating at 200 rpm. If length of connecting rod is 8 mts and crank shaft is 2 mts, velocity of crosshead at 30? rotation of crank shaft equals. a.30.2 m/s b.33.2 m/s c.35.8 mts/s d.107 dynes e.25.5 m/s

Last Answer : e. 25.5 m/s

Description : Which is the correct relationship for a centrifugal pump? (Where, D = Impeller diameter, inches H = Head developed, ft of liquid pumped N = Speed of pump, rpm) (A) D = 1840 H0.5 /N (B) D = 1840 N/H0.5 (C) H = 1840 D0.5 /N (D) D = 1840 H/N

Last Answer : (A) D = 1840 H0.5 /N

Description : In centrifugal pump installation,  (A) Pump is properly primed before starting  (B) The diameter of the pipe at inlet as well as at outlet, is kept smaller than the delivery pipe  (C) The ... out if it is started with empty delivery pipe and with open gate valve  (D) All the above 

Last Answer : (D) All the above 

Description : Theoretical capacity of crushing rolls in tons/hr is given by (where, V = peripheral velocity, m/sec. W = width of rolls, m Dr = distance between rolls ρ = density of material to be crushed, kg/m3 here, V =πND where, N = speed of the rolls ... V.W.Dr.ρ (B) 3.6 V.W. ρ (C) 3.6 W.Dr.ρ (D) 3.6 V.W.Dr/ρ

Last Answer : (A) 3.6 V.W.Dr.ρ

Description : A centrifugal pump has the following specifications: Power = 4 H.P.; Speed = 800 rpm Head = 8 metres Flow = 1000 litres/minutes. If its speed is halved, the power consumed now will be __________ hp. (A) 0.5 (B) 2 (C) 4 (D) 1

Last Answer : (A) 0.5

Description : A centrifugal pump has the following specifications: Power = 4 H.P.; Speed = 800 rpm Head = 8 metres Flow = 1000 litres/minutes. If its speed is halved, then the new head will be __________ metres. (A) 2 (B) 4 (C) 8 (D) 5.5

Last Answer : (A) 2

Description : A centrifugal pump has the following specifications: Power = 4 H.P.; Speed = 800 rpm Head = 8 metres Flow = 1000 litres/minutes. If its speed is halved, the new discharge will be __________ litres/minute. (A) 500 (B) 200 (C) 1000 (D) 750

Last Answer : (A) 500

Description : In case of unsteady fluid flow, conditions & flow pattern change with the passage of time at a position in a flow situation. Which of the following is an example of unsteady flow? (A) ... level is maintained (D) Low velocity flow of a highly viscous liquid through a hydraulically smooth pipe

Last Answer : (B) Water flow in the suction and discharge pipe of a reciprocating pump

Description : Conversion of dynamic velocity head into static pressure head in a centrifugal pump is the result of : (a) Increasing area of flow between adjacent vanes from inlet to outlet (b) Difference in pressure between suction and delivery ends (c) Radial thrust in pumps (d) Stuffing Box

Last Answer : (b) Difference in pressure between suction and delivery ends

Description : The variable required to be known in correlations used for estimating the horse power of a centrifugal gas compressor and hence its cost is P. Inlet pressure Q. Compressor rpm R. Delivery pressure S. Volumetric flow rate at inlet. (A) P, Q and R (B) P and R (C) R and S (D) P, Rand S

Last Answer : (A) P, Q and R

Description : In case of a centrifugal pump, the theoretical head developed is dependent on the __________ the impeller. (A) Speed of (B) Diameter of (C) Fluid velocity leaving (D) All (A), (B) and (C)

Last Answer : (D) All (A), (B) and (C)

Description : A flywheel 200 cm in diameter is rotating at 100 rpm. A point on the rim of the flywheel will not have a.angular velocity b.centripental acceleration c.tangential acceleration d.all of the above e.107 dynes

Last Answer : c. tangential acceleration

Description : A flywheel 200 cm in diameter is rotating at 100 rpm. A point one the rim of the flywheel will not have a.angular velocity b.centripetal acceleration c.tangential acceleration d.all of the above e.107 dynes

Last Answer : a. angular velocity

Description : Delivery of insufficient quantity of liquid by a pump may be caused by (A) Air leak in the inlet (B) Low rpm (C) Too high a lift (D) All (A), (B) and (C)

Last Answer : (D) All (A), (B) and (C)

Description : A centrifugal pump is called a turbine pump, if it is having a (A) Turbine type impeller (B) Vaned diffusion casing (C) Rotating vaned volute (D) None of these

Last Answer : (B) Vaned diffusion casing

Description : A fluid (µ/ρ) = 0.01 cm2 /sec is moving at critical flow condition (NRe = 2100) through a pipe of dia 3 cms. Velocity of flow is __________ cm/sec. (A) 7 (B) 700 (C) 7000 (D) 630

Last Answer : (A) 7

Description : Consider a centrifugal pump having a specific impeller diameter, fixed impeller speed pumping a liquid of constant density at a particular discharge capacity. With decrease in the capacity of the pump, the __________ decreases. (A) ... the pump (C) Head of the liquid pumped (D) All (A), (B) and (C)

Last Answer : (D) All (A), (B) and (C)

Description : Cavitation in a centrifugal pump can be avoided by keeping the (A) Inlet pressure high (B) Outlet pressure low (C) Inlet pressure low (D) Outlet pressure high

Last Answer : (A) Inlet pressure high

Description : The equivalent diameter of channel of a constant non-circular cross￾section of 3 cm by 6 cm will be __________ cms. (A) 20 (B) 12 (C) 8 (D) 2

Last Answer : (D) 2

Description : Centrifugal pump is normally classified on the basis of the (A) rpm (B) Type of casing (C) Impeller blade angle (D) Number of blades in impeller

Last Answer : (B) Type of casing

Description : A flywheel starting from rest and accelerating uniformly performs 25 revolutions in 5 sec. Its angular velocity in rpm after 10 seconds would be a.50 rpm b.20 rpm c.25 rpm d.60 rpm e.45 rpm

Last Answer : b. 20 rpm

Description : Power required by a centrifugal pump is proportional to (where, D = diameter, N = r.p.m) (A) N2D3 (B) ND2 (C) N2D (D) N3D5

Last Answer : (D) N3D5

Description : A 100 kg flywheel having a radius of gyration of 1 m is rotating at 1000 rpm. The angular momentum of the flywheel about its axis of rotation, in kg m2/s is a.1000 b.107 dynes c.10000 d.10470 e.5235

Last Answer : d. 10470

Description : At a constant speed of the centrifugal pump, it’s __________ the impeller diameter. (A) Capacity varies directly with (B) Head varies as the square of (C) Horsepower varies as the cube of (D) All (A), (B) and (C)

Last Answer : (D) All (A), (B) and (C)

Description : Rod mills employed for grinding (A) Employ a steel shell having L/D ratio of 1.5 to 3.0 (B) Is useful for handling sticky materials (C) Employ steel rods of 2-12 cms diameter extending over full length of the mill (D) All 'a', 'b' & 'c'

Last Answer : (D) All 'a', 'b' & 'c'

Description : Main boring diameter for petroleum well is 20-30 cms in diameter, while the depth of the oil well may be about __________ kms. (A) 0.1 to 0.5 (B) 1.5 to 4.5 (C) 7.5 to 12.5 (D) 15-20

Last Answer : (B) 1.5 to 4.5

Description : A ____ pump consists of a reciprocating or rotating cavity between two lobes or gears and a rotor. a. positive c. negative b. centrifugal d. hand

Last Answer : a. positive

Description : For a peak discharge of 0.0157 cumec, with a velocity of 0.9 m/sec, the diameter of the sewer main, is A. 10 cm B. 12 cm C. 15 cm D. 18 cm

Last Answer : ANS: C

Description : Theoretical head developed by a centrifugal pump does not depend upon the __________ the impeller. (A) Radius of (B) Speed of (C) Fluid velocity leaving (D) None of these

Last Answer : (D) None of these

Description : A dash pot consists of a cylinder 10 cm in diameter in which slides a piston 12 cm long having a radial clearance of 1 mm. The cylinder is filled with oil having a viscosity of 1 poise. What will be the resistance offered ... with a velocity of 3 cm/sec a.1090 kg b.100 kg c.10900 kg d.10 kg e.50 kg

Last Answer : c. 10900 kg

Description : Cleaning of sugarcane is obtained at peripheral speed A. 12-15m/sec B. 18-20m/sec C. 20-25m/sec D. 25-30m/sec

Last Answer : B. 18-20m/sec

Description : The blades of a centrifugal impeller are said to be curved forward, if the __________ of the motion of impeller blades. (A) Inlet tip of a blade curves in a direction opposite to that (B) Outlet tip ... Inlet tip of a blade is towards the direction (D) Outlet tip of a blade is towards the direction

Last Answer : (D) Outlet tip of a blade is towards the direction

Description : A 400kW, 3 -phase, 440V, 50Hz induction motor has a speed of 950 rpm on full load. The machine has 6 poles. The value of slip for the machine will be (A) 0.06 (B) 0.10 (C) 0.04 (D) 0.05

Last Answer : A 400kW, 3 -phase, 440V, 50Hz induction motor has a speed of 950 rpm on full load. The machine has 6 poles. The value of slip for the machine will be 0.05

Description : Pick up the correct statement from the following: A. The sewer pipes of sizes less than 0.4 m diameter are designed as running full at maximum discharge B. The sewer pipes of sizes greater than 0.4 m ... discharge C. The minimum design velocity of sewer pipes is taken as 0.8 m/sec D. All the above

Last Answer : ANS: D

Description : Dust collection efficiency of a cyclone separator depends upon its (A) Diameter (B) Inlet gas velocity (C) Overall height (D) All (A), (B) & (C)

Last Answer : (D) All (A), (B) & (C)

Description : With a constant diameter impeller of a centrifugal pump (A) Its capacity varies directly as the square of speed (B) Head varies as the square of speed (C) Horsepower input varies as the square of speed (D) Head varies as the speed

Last Answer : (B) Head varies as the square of speed

Description : Head developed by a centrifugal pump depends on its (A) Speed (B) Impeller diameter (C) Both (A) and (B) (D) Neither (A) nor (B)

Last Answer : C) Both (A) and (B)

Description : The capacity of a centrifugal pump Can be increased by increasing the (A) Impeller diameter or speed (B) Number of pumps and joining them in series (C) Number of pumps and joining them in parallel (D) All (A), (B) and (C)

Last Answer : (D) All (A), (B) and (C)

Description : Nominal size of the discharge pipe of a pump is usually __________ the nominal size of the inlet pipe. (A) Smaller than (B) Larger than (C) Same as (D) Twice

Last Answer : (A) Smaller than

Description : Question No. 216 If the specific capacity of a well is 0.3183 × 10-3 per sec, the discharge from a well of 4 m diameter under a depression head of 4 m, is (A) 8 litres/sec (B) 10 litres/sec (C) 12 litres/sec (D) 16 litres/sec

Last Answer : (D) 16 litres/sec

Description : Maximum theoretical suction lift for water at 15°C by a centrifugal pump is 34 ft. The same for water at 90°C will be __________ ft. (A) 40 (B) 34 (C) 8 (D) 37

Last Answer : (C) 8

Description : A flywheel on a motor goes from rest to 1000 rpm in 6 sec. The number of revolutions made is  nearly equal to  (A) 25  (B) 50  (C) 100  (D) 250 

Last Answer : (B) 50 

Description : Volute type of casing is provided in a centrifugal pump to (A) Convert velocity head to pressure head (B) Convert pressure head to velocity head (C) Reduce the discharge fluctuation (D) Increase the discharge

Last Answer : (D) Increase the discharge

Description : What causes cavitation in centrifugal pump? (A) High suction pressure (B) Low barometric pressure (C) Low suction pressure (D) High suction velocity

Last Answer : (C) Low suction pressure

Description : The net positive suction head (NPSH) of a centrifugal pump is defined as the sum of the velocity head and the pressure head at the (A) Discharge (B) Suction (C) Suction minus vapor ... of the liquid at suction temperature (D) Discharge minus vapor pressure of the liquid at the discharge temperature

Last Answer : (C) Suction minus vapor pressure of the liquid at suction temperature

Description : The net positive suction head (NPSH) of a centrifugal pump is defined as the sum of the velocity head and the pressure head at the (A) Discharge (B) Suction (C) Suction minus vapor ... of the liquid at suction temperature (D) Discharge minus vapor pressure of the liquid at the discharge temperature

Last Answer : (C) Suction minus vapor pressure of the liquid at suction temperature

Description : Volute of a centrifugal pump should be designed in a fashion, such that the (A) Kinetic head gets converted into static head (B) Moving stream gradually reduces velocity (C) Mean velocity remains constant (D) None of these

Last Answer : (A) Kinetic head gets converted into static head

Description : Which of the following is not the function of a volute casing provided in a centrifugal pump? (A) To reduce the head loss in discharge (B) To increase the pump efficiency (C) To collect liquid ... and to transmit it to the delivery pipe at constant velocity (D) To increase the pump discharge rate

Last Answer : Option D

Description : A hydraulic press has a ram of 10 cms in diameter and a plunger of 1 cm in diameter. The force required on the plunger to raise a weight of 10 tons on the ram is __________ kg. (A) 10 (B) 100 (C) 1000 (D) 10000

Last Answer : (B) 100