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 = 39 m

A pump delivers 200 L/s of water (ρ = 1000 kg/m³) against a total head of 39 m. Use g = 9.81 m/s². Find the hydraulic power Ph given to the water, in kW.

Q = 200 L/sH = 39 mρ = 1000 kg/m³g = 9.81 m/s²
Ph = kW
2.Easy
PQ = 15 L/sH = 72 m

A pump delivers 15 L/s of water (ρ = 1000 kg/m³) against a total head of 72 m. Use g = 9.81 m/s². Find the hydraulic power Ph given to the water, in kW.

Q = 15 L/sH = 72 mρ = 1000 kg/m³g = 9.81 m/s²
Ph = kW
3.Medium
PQ = 25 L/sH = 66 m

In a test, a pump delivers 25 L/s of water (ρ = 1000 kg/m³) against a head of 66 m while its shaft takes 19 kW. Use g = 9.81 m/s². Find the pump efficiency η in percent.

Q = 25 L/sH = 66 mPshaft = 19 kWg = 9.81 m/s²
η = %
4.Medium
PQ = 50 L/sH = 78 m

A pump delivers 50 L/s of water (ρ = 1000 kg/m³) against a head of 78 m. The pump efficiency is 85% and the electric motor driving it has an efficiency of 88%. Use g = 9.81 m/s². Find the electrical power Pel the motor draws, in kW.

Q = 50 L/sH = 78 mηpump = 85%ηmotor = 88%g = 9.81 m/s²
Pel = kW
5.Hard
400 kPa (gauge)PQ = 60 L/sΔz = 9 mL = 400 m, D = 200 mm, f = 0.02, ΣK = 8

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 9 m higher. The pipe is 400 m long with an inside diameter of 200 mm and a Darcy friction factor f = 0.02; the minor-loss coefficients add up to ΣK = 8 (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 400 kPa. Find the head H the pump must add.

Q = 60 L/sΔz = 9 mL = 400 mD = 200 mmf = 0.02ΣK = 8ptank = 400 kPa
H = m
6.Hard
PQ = 120 L/sΔz = 7 mL = 500 m, D = 250 mm, f = 0.022, 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 7 m higher. The pipe is 500 m long with an inside diameter of 250 mm and a Darcy friction factor f = 0.022; the minor-loss coefficients add up to ΣK = 6 (entrance and exit included). Use g = 9.81 m/s². Find the head H the pump must add.

Q = 120 L/sΔz = 7 mL = 500 mD = 250 mmf = 0.022ΣK = 6
H = m

Answer key

  1. 1. Ph = 76.52 kW
  2. 2. Ph = 10.59 kW
  3. 3. η = 85.19 %
  4. 4. Pel = 51.15 kW
  5. 5. H = 58.7 m
  6. 6. H = 22.23 m

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