The shape factor of the section shown in the below figure is

Group symbols assigned to silty sand and clayey sand are respectively

In a BOD test using 5% dilution of the sample (15 ML of sample and 285 mL of dilution water), dissolved oxygen values for the sample and dilution water blank bottles after five days incubation at 20°C were 3.80 and 8.80 mg/L. respectively. Dissolved oxygen originally present in the undiluted sample was 0.80 mg/L. The 5-day 20°C BOD of the sample is

The influence line diagram for the force in member 'a' of the truss shown below is given by

A footing 2 m x 1 m exerts a uniform pressure of 150 kN/m² on the soil. Assuming a load dispersion of 2 vertical to 1 horizontal the average vertical stress (kN/m²) at 1.0 m below the footing is