A. a pipe laid on, or projecting above the undisturbed ground and covered with fills, is proportional to the square of the external diameter of the pipe
B. a flexible pipe burried in narrow trenches and thoroughly compacted side fills, is proportional to the product of the width of the trench and diameter of the pipe
C. a rigid pipe burried in a narrow trenches and thoroughly compacted side fills, is proportional to the square of the width of the trench
7. In a reservoir the average volume of sediment deposition is 0.15 million cubic per year. If the dead storage and total capacity of the reservoir are 8 million cubic metres and 36 million cubic metres respectively,
Options
A. the reservoir will theoretically be silted in 240 years
B. the reservoir will start reducing after 60 years