Correct Answer : Al of the above
Explaination : * At a particular speed of operation, the head produced decreases with the increase of discharge
* At a particular speed the discharge at which efficiency of a pump is maximum, is known as normal discharge
* The brake horse power required from the primemover to drive the pump, increases with the increase of discharge
* At zero discharge, discharge valve remaining closed, the head developed is maximum which is known as shut-off head