Test 7 (T3.2)

Choose the false statement:

• Volumetric machines provide a constant flow independently of pressure

• The efficiency of fluid-dynamic pumps is zero when they give their maximum flow

• The efficiency of fluid-dynamic pumps is zero when they give their maximum head

• The performance of fluid-dynamic pumps is minimum when they give their minimum flow and

  maximum when they give their maximum flow

About cavitation in fans, the most likely place where it can appear is:

• In the inlet section for flow rates greater than the design flow rate

• In the inlet section for flow rates less than the design flow rate

• In the outlet section if there are obstructions that cause the pressure to increase

• None of the above

About NPSH (Net Positive Suction Head):

• Is the suction head of a pump and corresponds to the maximum suction head above which cavitation

  appears

• It only occurs in fluid-dynamic pumps but not in volumetric pumps

• Is the suction head of a pump and corresponds to the maximum pressure it can give above which

  cavitation appears

• It only occurs in volumetric pumps but not in fluid-dynamic pumps

What do the Euler equations for pumps describe?

• The efficiency of a pump in converting mechanical power into fluid power

• The relationship between pressure and flow rate in a pump

• The structural integrity of a pump's components

• The speed of rotation required for optimal pump performance

In the Euler equations for pumps, what does the term "head" refer to?

• The rotational speed of the pump

• The physical height of the pump above the fluid level

• The diameter of the pump's impeller

• The energy imparted to the fluid by the pump