Question

746 - Calculate the water distribution efficiency, if the depths of penetration along the
length of a border strip at an interval of 20 m are 1.5 m, 1.8 m and 2.1 m respectively.
1) 0.6667
2) 0.8333
3) 0.8889
4) 0.9767​

Answer 1

Here is the solution:

Option 4 is correct

Explanation:

Mean depth, D = (2.0 + 1.9 + 1.8 + 1.6 + 1.5)/5 = 1.76 m

Values of deviations from the mean are (2.0 – 1.76), (1.9 – 1.76), (1.8 – 1.76), (1.6 – 1.76), (1.5 – 1.76)

= 0.24, 0.14, 0.04, – 0.16, – 0.26

The absolute values of these deviations from the mean are 0.24, 0.14, 0.04, 0.16, and 0.26

The average of these absolute values of deviations from the mean,

d = (0.24 + 0.14 + 0.04 + 0.16 + 0.26)/5 = 0.168 m

The water distribution efficiency, ηd =  (1- d/D) = (  1- 0.168/1.76)

= 0.905 × 100 = 90.5%