As per the relevant Bureau of Indian Standards (BIS) guidelines, what is the standard reference temperature specified for reporting the specific gravity of soils?

A dense sand at very low confining stress in a drained triaxial test is likely to show:

Which of the following methods is/are used to determine the in-situ density of soil? I. Sand replacement method II. Core cutter method

In the context of the soil classification system, what is the A-line equation in Casagrande's plasticity chart? (where Ip = plasticity index, wL = liquid limit)