A phreatic line is defined as the line within a dam section below which there are

ANS:B - positive hydrostatic pressure

The top flow line of a saturated soil mass below which seepage takes place, is called the Phreatic line. Hydrostatic pressure acts below the phreatic line whereas atmospheric pressure exists above the phreatic line. This line separates a saturated soil mass from an unsaturated soil mass. It is not an equipotential line, but a flow line. The top surface of a freely moving groundwater reservoir over an impervious stratum is called the Phreatic line or ground water table. Water pressure is atmosphere pressure at all points on a phreatic line so it is an equipotential line.