Pumps & pump power worksheet with answers

Free printable Pumps & pump power worksheet: 6 problems from easy to exam level, with an answer key. Print it or save it as a PDF.

New worksheetPractise online with hints

For teachers: free to print, copy and use in class. Every new worksheet has new values and its own answer key. A link to ExamProblems on your course page is appreciated.

Name: ____________________   Date: ____________

1.Easy
PQ = 200 L/sH = 48 m

A pump delivers 200 L/s of water (ρ = 1000 kg/m³) against a total head of 48 m. Use g = 9.81 m/s². Find the hydraulic power Ph given to the water, in kW.

Q = 200 L/sH = 48 mρ = 1000 kg/m³g = 9.81 m/s²
Ph = kW
2.Easy
PQ = 50 L/sH = ?

A pump delivers 50 L/s of water (ρ = 1000 kg/m³) and gives it a hydraulic power of 30 kW. Use g = 9.81 m/s². Find the head H the pump adds.

Ph = 30 kWQ = 50 L/sρ = 1000 kg/m³g = 9.81 m/s²
H = m
3.Medium
PQ = 15 L/sH = 48 m

A pump delivers 15 L/s of water (ρ = 1000 kg/m³) against a head of 48 m. The pump efficiency is 60% and the electric motor driving it has an efficiency of 95%. Use g = 9.81 m/s². Find the electrical power Pel the motor draws, in kW.

Q = 15 L/sH = 48 mηpump = 60%ηmotor = 95%g = 9.81 m/s²
Pel = kW
4.Medium
PQ = 100 L/sH = 68 m

A pump delivers 100 L/s of water (ρ = 1000 kg/m³) against a head of 68 m. The pump efficiency is 70% and the electric motor driving it has an efficiency of 94%. Use g = 9.81 m/s². Find the electrical power Pel the motor draws, in kW.

Q = 100 L/sH = 68 mηpump = 70%ηmotor = 94%g = 9.81 m/s²
Pel = kW
5.Hard
350 kPa (gauge)PQ = 120 L/sΔz = 10 mL = 400 m, D = 250 mm, f = 0.015, ΣK = 6

A pump moves 120 L/s of water (ρ = 1000 kg/m³) from an open lower reservoir to an upper tank whose water surface is 10 m higher. The pipe is 400 m long with an inside diameter of 250 mm and a Darcy friction factor f = 0.015; the minor-loss coefficients add up to ΣK = 6 (entrance and exit included). Use g = 9.81 m/s². The upper tank is closed and the air above its water is at a gauge pressure of 350 kPa. Find the head H the pump must add.

Q = 120 L/sΔz = 10 mL = 400 mD = 250 mmf = 0.015ΣK = 6ptank = 350 kPa
H = m
6.Hard
PQ = 50 L/sΔz = 9 mL = 500 m, D = 150 mm, f = 0.015, ΣK = 5

A pump moves 50 L/s of water (ρ = 1000 kg/m³) from an open lower reservoir to an upper tank whose water surface is 9 m higher. The pipe is 500 m long with an inside diameter of 150 mm and a Darcy friction factor f = 0.015; the minor-loss coefficients add up to ΣK = 5 (entrance and exit included). Use g = 9.81 m/s². The pump efficiency is 75%. Find the shaft power Pshaft in kW.

Q = 50 L/sΔz = 9 mL = 500 mD = 150 mmf = 0.015ΣK = 5η = 75%
Pshaft = kW

Answer key

  1. 1. Ph = 94.18 kW
  2. 2. H = 61.16 m
  3. 3. Pel = 12.39 kW
  4. 4. Pel = 101.4 kW
  5. 5. H = 54.82 m
  6. 6. Pshaft = 20.56 kW

Full step-by-step solutions: practise this topic on examproblems.com.