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.

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1.Easy
PQ = 15 L/sH = 29 m

A pump delivers 15 L/s of water (ρ = 1000 kg/m³) against a total head of 29 m. Use g = 9.81 m/s². Find the hydraulic power Ph given to the water, in kW.

Q = 15 L/sH = 29 mρ = 1000 kg/m³g = 9.81 m/s²
Ph = kW
2.Easy
PQ = 8 L/sH = 39 m

A pump delivers 8 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 = 8 L/sH = 39 mρ = 1000 kg/m³g = 9.81 m/s²
Ph = kW
3.Medium
PQ = 10 L/sH = 52 m

A pump delivers 10 L/s of water (ρ = 1000 kg/m³) against a head of 52 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 = 10 L/sH = 52 mηpump = 85%ηmotor = 88%g = 9.81 m/s²
Pel = kW
4.Medium
PQ = 80 L/sH = 44 m

In a test, a pump delivers 80 L/s of water (ρ = 1000 kg/m³) against a head of 44 m while its shaft takes 43.2 kW. Use g = 9.81 m/s². Find the pump efficiency η in percent.

Q = 80 L/sH = 44 mPshaft = 43.2 kWg = 9.81 m/s²
η = %
5.Hard
PQ = 50 L/sΔz = 6 mL = 200 m, D = 150 mm, f = 0.025, ΣK = 4

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 6 m higher. The pipe is 200 m long with an inside diameter of 150 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 = 50 L/sΔz = 6 mL = 200 mD = 150 mmf = 0.025ΣK = 4
H = m
6.Hard
250 kPa (gauge)PQ = 30 L/sΔz = 10 mL = 200 m, D = 150 mm, f = 0.025, ΣK = 8

A pump moves 30 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 200 m long with an inside diameter of 150 mm and a Darcy friction factor f = 0.025; 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 250 kPa. Find the head H the pump must add.

Q = 30 L/sΔz = 10 mL = 200 mD = 150 mmf = 0.025ΣK = 8ptank = 250 kPa
H = m

Answer key

  1. 1. Ph = 4.267 kW
  2. 2. Ph = 3.061 kW
  3. 3. Pel = 6.82 kW
  4. 4. η = 79.93 %
  5. 5. H = 21.23 m
  6. 6. H = 41.56 m

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