During seepage through an earth dam, the direction of seepage is
- AParallel to the equipotential lines
- BPerpendicular to the stream lines
- CPerpendicular to the equipotential linesCorrect
- DAlong the direction of gravity
Solution
Concept
Flow lines and equipotential lines
Step-by-step solution
1. Seepage takes place along flow (stream) lines. 2. Flow lines and equipotential lines intersect at right angles. 3. So the direction of seepage is perpendicular to the equipotential lines.
Explanation
Water flows in the direction of the head decrease, which is at right angles to the equipotential lines (lines of equal head) in an isotropic soil.
Shortcut
Flow lines ⟂ equipotential lines.
Common mistake
Choosing along the direction of gravity.
Correct answer: C) Perpendicular to the equipotential lines