Length of soil sample for constant head permeability test is 30 cm, Area of specimen is 177cm², constant head difference is 50 cm, total volume of water collected in 5 min is 350cm³. Calculate the hydraulic conductivity of the soil. A) 2.85×10' cm/sec D) 1.09×10² cm/sec B) 1.09×10 cm/sec C) 3.95×10³ cm/sec B Calculate the ultimate BOD of the river when an effluent is discharged into it. Stream: Q,-8.70 m³/s BOD=6mg/L Effluent: Q.-1.10 m³/s BOD-50 mg/L k₁ = 0.20/day A) 10.9 mg/L B) 5.4 mg/L C) 2.6 mg/L D) 12.6 mg/L Find the error in the discharge when a head of water over the crest of a triangular weir is measured, an error of 1% is observed. A)1.0 B)2.0 C)1.5 D)2.5 Calculate the hydraulic depth of the rectangular channel of 12 ft wide and carrying water of depth 3 ft. A) 2.22 ft A B B)3.6 ft C)4.0 ft D)4.23 ft.