Question 1: At 15.6°C,the speed of sound through water is:
A - 146.9 m/s B - 14.69 m/s C - 1469 m/s D - 1.469 m/s _______________________________________________
Question 2: Calculate the volumetric efficiency, expressed as a percentage, for a reciprocating pump where the pump piston displaces 3.50 litres but only 3.36 litres are forced into the discharge. A - 96% B - 9.6% C - 69% D - 4% _______________________________________________
Question 3: Several factors govern the rating of a centrifugal pump. When considering the effects of pump impeller diameter, all of the following statements are untrue except: A - Capacity is directly proportional to the impeller diameter B - Power is directly proportional to the square of the impeller diameter C - Head in metres or pressure in kPa is directly proportional to the impeller diameter D - Head in metres or pressure in kPa is directly proportional to the cube of the impeller diameter _______________________________________________
Question 4: Water hammer is the result of a pressure wave that is created in a liquid by a sudden change in flow rate. The maximum intensity of the wave can be calculated by Joukowsky's Law. Of the values represented in the formula: Hwh = , all of the following are correct except:
A - c = velocity of sound in the liquid, m/s B - g = acceleration due to gravity, 9.81 m/s2 C - v = instantaneous velocity change in liquid (m/s) D - All of the above _______________________________________________
Question 5: In a reciprocating pump, the volumetric efficiency is the ratio of the volume of liquid delivered to the: A - Pump discharge B - Suction head C - Piston displacement D - Stuffing box _______________________________________________
Question 6: A pump delivers water to a tank 50 metres above the pump. Assume that the water is at 15.6°C.The power fails and the pump discharge check valve is jammed open for a few seconds and then finally slams shut. Before the check valve can close, water begins to flow backwards through the pump at a velocity of 20 metres per second, causing water hammer. What is the pressure produced by the total head produced when the water hammer occurred? A - 29,380.95 kPa B - 3054.81 kPa C - 15,181 kPa D - 29,871.45 kPa _______________________________________________
Question 7:
A pump delivers water to a tank 35 metres above the pump. Assume that the water is at 15.6°C. The pump is shutdown and the pump discharge check valve is jammed open for a few seconds and then closes. Before the valve closes, water begins to flow backwards through the pump at a velocity of 15 metres per second, causing water hammer. What is the pressure produced by the total head produced when the water hammer occurred? A - 15,681.88 kPa B - 22,745.92 kPa C - 22,033.26 kPa D - 22,376.61 kPa _______________________________________________
Question 8: In centrifugal pumps, the input power is the power supplied by the drive unit, known as:
A - Capacity B - Volumetric efficiency C - Liquid kW D - Brake kW _______________________________________________
Question 9: Based on the pump performance curves in the illustration shown here, this pump performs best when the head is between ________________, with the efficiency near____%.
A - 108 and 120, 100 B - 90 and 110, 90 C - 80 and 90, 100 D - 96 and 108, 90 _______________________________________________
Question 10: Calculate the slip, in litres/stroke, for a reciprocating pump where the piston displaces 1.50 litres but only 1.32 litres are forced into the discharge. A - 0.018 B - 1.80 C - 0.18 D - 0.8 _______________________________________________
Question 11: To calculate the work done upon the water being pumped, the correct formula is: A - Pump power = m³/s x kg/m³ x total head (m) x 9.81 m/s² B - Pump power = m³/s x kg/m³ x suction head (m) x 9.81 m/s² C - Pump power = m³/s x kg/m³ x static head (m) x 9.81 m/s² D - Pump power = m³/s x kg/m³ x discharge head (m) x 9.81 m/s² _______________________________________________
Question 12: In a system where two pumps are used to draw water from a stream and pump it 8 km to a holding pond, the best way to avoid damage from water hammer would be to stage the pump start-ups so that water hammer from the first pump has subsided before the next pump is added.
A - True B - False _______________________________________________
Question 13: Positive displacement pumps are capable of maintaining a: A - Varied discharge quantity against varying suction pressure B - Varied discharge quantity against varying discharge pressure C - Fixed discharge quantity against varying suction pressure D - Fixed discharge quantity against varying discharge pressure _______________________________________________
Question 14: Several factors govern the rating of a centrifugal pump. When considering the effects of pump speed change, all of the following statements are true except: A - Capacity (Q) is directly proportional to the square of the speed (N2) B - Capacity (Q) is directly proportional to speed (N) C - Power (kW) is directly proportional to the cube of the speed (N3) D - Head in metres or pressure in kPa (P) is directly proportional to the square of the speed (N2) _______________________________________________
Question 15: A pump delivers water to a tank 35 metres above the pump. Assume that the water is at 15.6°C.Assume the speed of sound in water is 1469 m/s at 15.6 ºC. The pump is shutdown and the pump discharge check valve is jammed open for a few seconds and then shuts. Before the check valve closes, water begins to flow backwards through the pump at a velocity of 15 metres per second, causing water hammer. Calculate the total head produced when the water hammer occurred.
A - 1856 m B - 1513 m C - 2246 m D - 2281 m _______________________________________________
Question 16: When calculating the pump input power, an allowance must be made for pump: A - Capacity B - Efficiency C - Discharge rate D - All of the above _______________________________________________
Question 17: With rotary pumps, the pump power varies: A - Directly with the discharge pressure B - With the pump speed C - Inversely with the discharge pressure D - Both a and b _______________________________________________
Question 18: Calculate the slip, in litres/stroke, for a reciprocating pump where the pump piston displaces 1.75 litres but only 1.49 litres are forced into the discharge. A - 0.26 B - .026 C - 0.851 D - 1.174 _______________________________________________
Question 19: A pump delivers water to a tank 50 metres above the pump. Assume that the water is at 15.6°C. Assume the speed of sound in water is 1469 m/s at 15.6 ºC.The power fails and the pump discharge check valve is jammed open for a few seconds and then finally slams shut. Before the check valve can close, water begins to flow backwards through the pump at a velocity of 20 metres per second, causing water hammer. Calculate the total head produced when the water hammer occurred.
, all of the following are correct except: 