Description : A pump operating under specific conditions delivers insufficient quantity of liquid. This may be set right by (A) Decreasing the size of the inlet pipe (B) Increasing the size of the inlet pipe (C) Lowering the pump position (D) Both (B) and (C)
Last Answer : (D) Both (B) and (C)
Description : A centrifugal pump loses prime after starting. The reason of this trouble may be (A) Incomplete priming (B) Too high a suction lift (C) Low available NPSH and air leaks in the suction pipe (D) All (A), (B), and (C)
Last Answer : (D) All (A), (B), and (C)
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 : 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
Last Answer : (B) 12.4
Description : A leak in the bottom of a bunker can empty the full bunker in 4 hrs. An inlet pump fills water at the rate of 3 litres a min. when the bunker is full, the inlet is opened and due to the leak, ... hrs. How many litres does the bunker field? A) 1160 litrs B) 1610 litres C) 2160 litres D) 2610 litres
Last Answer : C Work done by the inlet in 1 hr = (1/4 – 1/6) = (3-2/12) = 1/12 Work done by the inlet in 1 min = 1/12 * 1/60 = 1/720 Volume of 1/720 part = 3 litres Volume of whole = (720 * 3 )=2160 litres.
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 : If the discharge of a centrifugal pump is throttled, then its suction lift (A) Increases (B) Decreases (C) Remains unchanged (D) Data insufficient to predict
Last Answer : (A) Increases
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 : 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 : Consider the following statements: The total head against which a pump has to work must include, besides any other items, 1. the suction lift. 2. the delivery head. 3. the head lost due to friction at entrance in the rising main. 4. the ... 2 & 3 only (b) 2 & 3 only (c) 1, 2, 3 & 4 (d) 3 & 4 only
Last Answer : (c) 1, 2, 3 & 4
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 : A liquid/gaseous fuel containing hydrocarbons and high amount of sulphur is burnt with 40% excess air. The flue gas still contains large amount of carbon monoxide. This may be due to the (A) Presence of large ... fuel (C) High sulphur content in the fuel (D) Lack of thorough mixing of fuel with air
Last Answer : (D) Lack of thorough mixing of fuel with air
Description : A tank can be filled by an inlet tap at the rate of 8 litres per minute. A leak in the bottom of a tank can empty the full tank in 16 hours. When the tank is full, the inlet is opened and due to ... hours. How many litres does the tank hold? A) 8000 litre B) 9560 litre C) 8525 litre D) 9600 litre
Last Answer : D Part emptied by the leak in 1 hour = 1/16 part filled by (leak & inlet open) in 1 hour = 1/80 Part filled by the inlet tap in 1 hour = 1/16 – 1/80 = 1/20 Inlet tap fills the tank in = 20 hours Inlet tap fills water at the rate of 8 litres a minute. Capacity of tank = 20 * 60 * 8= 9600 litre
Description : Erosion and pits formation on the impeller of a centrifugal pump may be due to (A) Cavitation (B) Low speed of impeller (C) Its operation with delivery valve closed for considerable time after starting the pump (D) Off centering of pump with motor
Last Answer : (A) Cavitation
Description : Horsepower requirement for given pump capacity depends upon the (A) Specific gravity of the liquid (B) Suction lift (C) Discharge head (D) All (A), (B) and (C)
Last Answer : (D) All (A), (B) and (C)
Description : Actual lift of a pump is always less than the theoretical lift and is limited by the (A) Specific gravity & temperature of the liquid (B) Leakage & pressure decreasing at higher elevations (C) Frictional resistance through pipes, fittings & passages (D) All (A), (B) and (C)
Description : Mixing of air and fuel in the diesel engine occurs in a. injection pump b. carburetor c. engine cylinder d. inlet manifold
Last Answer : ANSWER c. engine cylinder
Description : A reciprocating compressor is not suitable for use as a supercharger because: A. it runs at lower rpm B. the pressure ratio is high C. volumetric efficiency is high D. it is bulky and can handle small quantity of air
Last Answer : ANSWER : D
Description : The _____________ sensor, monitors mass or volume of air flowing into the intake manifold for adjusting the quantity of fuel. a) engine temperature b) exhaust gas c) air flow d) air inlet temperature
Last Answer : Answer: c Explanation: The air flow sensor, monitors mass or volume of air flowing into the intake manifold for adjusting the quantity of fuel while exhaust gas senor senses the amount of oxygen in the engine exhaust and calculates air-fuel ratio.
Description : The main drawback of centrifugal pump is a)necessity of priming b) discharge from pump varies with the load of water c) For high heads efficiency is low up to 50% d) the suction lift is limited to 6 metre e) all of the above*
Last Answer : e) all of the above*
Description : It is the unbalanced force developed in a turbo jet engine that is caused by the difference in the momentum of the low-velocity air entering the engine and the high velocity exhaust gases leaving the engine. a. Fall b. Lift c. Drag d. Thrust
Last Answer : Thrust
Description : Marginal leakage at the proximal gingival cavosurface of a recently restored class II can be caused by: I. Insufficient condensation II. First proximal increment was too large III. Neglecting to wedge the matrix IV. Hand ... III, IV C. I, II, V D. None of the above E. All of the above
Last Answer : C. I, II, V
Description : Liquid delivery by centrifugal pump starts, only when the head developed by it is equal to the __________ head. (A) Manometric (B) Total (C) Static (D) Friction
Last Answer : (A) Manometric
Description : Hydraulic intensifier is used for increasing the (A) Rate of velocity of liquid supply (B) Rate of flow through delivery pipeline of a pump (C) Intensity of pressure of the liquid (D) Momentum rate through delivery pipe
Last Answer : (C) Intensity of pressure of the liquid
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 : 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 : A centrifugal pump used to pump water is used to pump an oil withspecific gravity of 0.8 at the same rate. The power consumption will now (A) Increase (B) Decrease (C) Remain same (D) Data insufficient to predict
Last Answer : (B) Decrease
Description : Purpose of air lift pump is to (A) Compress air (B) Lift compressed air (C) Lift water from a well by using compressed air (D) Lift air under negative pressure
Last Answer : (C) Lift water from a well by using compressed air
Description : What type of pump may be appropriate for a liquid near saturation, a low flow rate, and very limited NPSHa (net positive suction head available)?
Last Answer : This application is nearly perfect for a turbine regenerative type of pump. Factors that immediately identify your application and pump type are the small flowrate, low NPSHa, and high temperature. The ... in pressure. You can visit the site below to learn more about these types of pumps.
Description : Articles the addresses of which are so illegible or incomplete as to render delivery impossible are called a) Insufficient address article b) Undeliverable articles c) Refused article d) Undelivered articles
Last Answer : b) Undeliverable articles
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 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 : Pick up the correct statement from the following: (A) Insufficient quantity of water makes the concrete mix harsh (B) Insufficient quantity of water makes the concrete unworkable (C) Excess quantity of water makes the concrete segregated (D) All the above
Description : Insufficient quantity of water (a) Makes the concrete mix harsh (b) Makes the concrete mix unworkable (c) Causes segregation in concrete (d) Causes bleeding in concrete.
Last Answer : both a&b
Description : Pump A can fill the empty bunker in 6 hours, but due to a leak in the bottom it is filled in 7.5 hours, if the bunker is full and then Pump A is closed then in how many hours the leak can empty it? a) 30 hours. b) 45 hours. c) 50 hours. d) 35 hours.
Last Answer : A Efficiency of A = 16.666% Effective of leak = 13.333%when there is leakage So, efficiency of leakage =( Efficiency of A- Effective of leak) =16.666%-13.333%= 3.333% It means due to leakage a full bunker will be empty in 30 hours.
Description : An electric pump can fill a cistern in 6 hrs. Because of a leak in the cistern it took 7 hrs to fill the cistern. If the cistern is full, how much time will the leak take to empty it? A) 42hrs B) 24hrs C) 32hrs D) 16hrs
Last Answer : A Work done by the leak in 1 hr = [1/6 – 1/7] = 7-6/42 =1/42 Therefore the leak will empty the cistern in 42 hrs.
Description : Compound A is extracted from a solution of A + B into a pure solvent S. A Co-current unit is used for the liquid-liquid extraction. The inlet rate of the solution containing A is 200 moles of B/hr.m2 and the ... extraction achieved in the unit is (A) 25% (B) 50% (C) 70% (D) 90%
Last Answer : (B) 50%
Description : At the same gas flow rate, the pressure drop in a packed tower being irrigated with liquid __________ that in dry packed tower. (A) Is greater than (B) Is lower than (C) Is same as (D) Cannot be predicted as data are insufficient
Last Answer : (A) Is greater than
Description : Reynolds number for water flow through a tube of I.D. 5 cm is 1500. If a liquid of 5 centipoise viscosity and 0.8 specific gravity flows in the same pipe at the same velocity, then the pressure drop will (A) Increase (B) Decrease (C) Remain same (D) Data insufficient to predict pressure drop
Last Answer : (A) Increase
Description : A cylinder contains 640 gm of liquid oxygen. The volume occupied (in litres) by the oxygen, when it is released and brought to standard conditions (0°C, 760 mm Hg) will be __________ litres. (A) 448 (B) 224 (C) 22.4 (D) Data insufficient; can't be computed
Last Answer : (A) 448
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 : What is the maximum theoretical suction lift (metres) of a reciprocating pump? (A) 5 (B) 10(C) 50 (D) 100
Last Answer : (B) 10
Description : Can a cooling tower cool water below the wet bulb temperature of inlet air? (A) Yes (B) No (C) Yes; but height of cooling tower will be prohibitively high (D) Yes; but the air flow rate should be excessively high
Last Answer : (B) No
Description : Consider the following statements: Air vessels are fitted on the suction and delivery sides of a reciprocating pump to 1. Achieve higher speed without separation. 2. Reduce work in overcoming frictional resistance. 3. Avoid excessive vibration ... 2 & 3 only (c) 2, 3 & 4 only (d) 1, 2, 3 & 4
Last Answer : (d) 1, 2, 3 & 4
Description : High temperature carbonisation of coal produces (A) Inferior coke compared to low temperature carbonisation (B) Less of gases compared to liquid products (C) Large quantity of tar compared to low temperature carbonisation (D) None of these
Last Answer : (D) None of these
Description : High temperature carbonisation of coal produces (A) Inferior coke compared to low temperature carbonisation (B) Less of gases compared to liquid products (C) Larger quantity of tar compared to low temperature carbonisation (D) None of these
Description : If Nordica offered a 25 percent discount to retailers that ordered ski boots in February for delivery in May, the retailer would have the option of taking advantage of which type of discount? A)Trade B)Cumulative C)Cash D)Quantity E)Seasonal
Last Answer : E)Seasonal