Answer: b) Casagrande
- Liquid limit is simply the moisture content at which soil changes from liquid to plastic state.
- Casagrande apparatus is used to test the liquid limit of soil. Casagrande apparatus consists of a rubber base & brass cup.
- A sample is filled in a cup, which is subjected to blows with a rotating handle with two revolutions per second.
- Experimentally, the liquid limit is the moisture content corresponding to 25 blows.