A weir across an alluvial river has a horizontal floor length of 54 m and retains 6 m of water under full pond conditions. If the downstream sheet pile is driven to a depth of 6 m below the average bed level, the exit gradient for this case is
1
1/(π √5) approx
2
1/(π /√2) approx
3
1/(π /√3) approx
4
1/(π /√6) approx
5
Question Not Attempted