Hydraulic Pumps MCQ | Centrifugal Pumps MCQ

51. Air vessel is used in a reciprocating pump to obtain

  1. reduction of suction head
  2. rise in delivery head
  3. increase in supply of water
  4. continuous supply of water at uniform rate
Answer
Answer. d

52. Two identical pumps, each capable of delivering 0.2 cumec, against a head of 30 m, are connected in parallel. The resulting discharge will be

  1. 0.4 cumec against a head of 30 m
  2. 0.4 cumec against a head of 60 m
  3. 0.2 cumec against a head of 60 m
  4. 0.2 cumec against a head of 30 m
Answer
Answer. a

53. The function of an air vessel in a reciprocation pump is to obtain

  1. reduction of suction head
  2. rise in delivery head
  3. continuous supply of water at uniform rate
  4. increase in supply of water
Answer
Answer. c

54. During suction stroke of a reciprocating pump, the separation may take place

  1. at the end of suction stroke
  2. in the middle of suction stroke
  3. at the beginning of suction stroke
  4. none of the above
Answer
Answer. c

55. A pump operating point is the intersection of

  1. Pumping head-discharge curve and the system head-discharge curve
  2. Pumping head-discharge curve and the efficiency curve
  3. System head-discharge curve and the efficiency of curve
  4. BHP line and efficiency curves
Answer
Answer. a

56. A high-efficiency pump is required for low discharge high head and low maintenance cost. Delivery of water need not be continuous. The pump need not run at high speed. Which one of the following is the correct choice?

  1. Reciprocating pump
  2. Centrifugal pump
  3. Hydraulic Ram
  4. Airlift pump
Answer
Answer. a

57. The control which will limit pump outlet pressure to a predetermined level and adjust to the level needed to maintain the set pressure, is

  1. pressure compensator control
  2. load sense control
  3. meter-in circuit
  4. meter-out circuit
Answer
Answer. a

58. The internal and external diameter of the impeller of a centrifugal pump are 200 mm and 400 mm respectively. The pump is running at 1200 r.p.m. The vane angles of the impeller at inlet and outlet are 20° and 30° respectively. The water enters the impeller radially and velocity of flow is constant. The tangential velocity at the inlet and outlet in m/s is

  1. 1.256, 25.13
  2. 12.56, 2.513
  3. 12.56, 25.13
  4. 125.6, 25.13
Answer
Answer. c

59. A centrifugal pump having outer diameter equal to two times the inner diameter and running at 1000 rpm. Works a total head of 40 m. The velocity of flow through the impeller is constant and equal to 2.5 m/s. The vanes are set back at an angle 40° at outlet. If the outer diameter of the impeller is 500 mm and width at outlet is 50 mm, the discharge is

  1. 1.963 m3/sec
  2. 0.1963 m3/min
  3. 0.1963 cm3/s
  4. 0.1963 m3/sec
Answer
Answer. d

60. What are the dimensions of the specific speed for a turbine?

  1. F0.5L-1.5T-1.5
  2. F0.5L-0.75T-1.5
  3. F0.5L-0.7T-0.5
  4. It is dimensionless
Answer
Answer. b