Q1: Which one of the following different types of submerged soils is susceptible to liquefaction under earthquake shocks ?

ANS:C - Loose silt

Liquefaction occurs in dense saturated or submerged sands. Even though the dense sands are strong under normal circumstances, under earthquake loads, the vibration causes foundations to sink in the sands thereby causing the sands to act as if they are liquid. Hence it is called liquefaction.