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 = 10 L/sH = ?

A pump delivers 10 L/s of water (ρ = 1000 kg/m³) and gives it a hydraulic power of 4 kW. Use g = 9.81 m/s². Find the head H the pump adds.

Ph = 4 kWQ = 10 L/sρ = 1000 kg/m³g = 9.81 m/s²
H = m
2.Easy
Δp = 200 kPaPQ = 10 L/s

A pump raises the pressure of 10 L/s of water by 200 kPa. Inlet and outlet are at the same height and have the same diameter. Find the hydraulic power Ph in kW.

Q = 10 L/sΔp = 200 kPa
Ph = kW
3.Medium
PQ = 30 L/sH = 60 m

In a test, a pump delivers 30 L/s of water (ρ = 1000 kg/m³) against a head of 60 m while its shaft takes 20.8 kW. Use g = 9.81 m/s². Find the pump efficiency η in percent.

Q = 30 L/sH = 60 mPshaft = 20.8 kWg = 9.81 m/s²
η = %
4.Medium
PQ = 30 L/sH = 24 m

A pump with an efficiency of 75% delivers 30 L/s of water (ρ = 1000 kg/m³) against a head of 24 m. Use g = 9.81 m/s². Find the shaft power Pshaft needed, in kW.

Q = 30 L/sH = 24 mη = 75%g = 9.81 m/s²
Pshaft = kW
5.Hard
350 kPa (gauge)PQ = 60 L/sΔz = 5 mL = 200 m, D = 250 mm, f = 0.025, ΣK = 5

A pump moves 60 L/s of water (ρ = 1000 kg/m³) from an open lower reservoir to an upper tank whose water surface is 5 m higher. The pipe is 200 m long with an inside diameter of 250 mm and a Darcy friction factor f = 0.025; the minor-loss coefficients add up to ΣK = 5 (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 = 60 L/sΔz = 5 mL = 200 mD = 250 mmf = 0.025ΣK = 5ptank = 350 kPa
H = m
6.Hard
PQ = 15 L/sΔz = 9 mL = 100 m, D = 100 mm, f = 0.025, ΣK = 4

A pump moves 15 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 100 m long with an inside diameter of 100 mm and a Darcy friction factor f = 0.025; the minor-loss coefficients add up to ΣK = 4 (entrance and exit included). Use g = 9.81 m/s². Find the head H the pump must add.

Q = 15 L/sΔz = 9 mL = 100 mD = 100 mmf = 0.025ΣK = 4
H = m

Answer key

  1. 1. H = 40.77 m
  2. 2. Ph = 2 kW
  3. 3. η = 84.89 %
  4. 4. Pshaft = 9.418 kW
  5. 5. H = 42.58 m
  6. 6. H = 14.39 m

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