The difference between the elevation of water surfaces in piezometers is _______
A : a. hydraulic gradient
B : b. velocity
C : c. head loss
D : d. depth or length of sample
The position head is also called ________
A : a. total head
B : b. elevation head
C : c. velocity head
D : d. pressure head
The elevation head is taken as negative if the point is situated above the datum and positive if below the datum.
The total head at any point may be regarded as _________ measure with respect to the datum.
A : a. potential energy
B : b. potential energy per unit weight of water
C : c. unit weight of water
D : d. volume of water