Problem $4$ Consider a typical centrifugal liquid pump. For each statement, choose whether the statement is true or false, and discuss your answer briefly.

$3$

$($a$)$ Volume flow rate at the pump's free delivery is greater than Volume flow rate at its best$-$efficiency point.

$($b$)$ At the pump's shutoff head, the pump efficiency is zero.

$($c$)$ At the pump's best efficiency point, its net head is at its maximum value.

$($d$)$ At the pump's free delivery, the pump efficiency is zero