Hand auger can be used for depths up to ____

The general exploration gives information about which of the following features?

When deeper layers have increasingly greater density, the seismic refraction method is fast.

The type of boring method that can be used for both rock and soils are ____

Exploratory borings in general exploration is carried out by using _______

In Dutch cone test, the cone along with mantle is further penetrated after 8cm to a depth of ____

To know the cone resistance, it is first forced down to _____ depth.

The cone test is very useful in ______