Correct Answer - Option 4 : greater than or equal to
A manometric head is defined as the head against which a centrifugal pump has to work.
Manometric head also measured as
Manometric head = Head imparted by the impeller to water – loss of head in the pump.
where,
Head imparted by the impeller to water = Manometric head + Loss of head in the pump.
Hence the Hydraulic pump will start pumping only when the pressure head is greater than or equal to the manometric head.
