For determining the ultimate bearing capacity of soil, the recommended size of a square bearing plate to be used in load plate test should be 30 to 75 cm square with a minimum thickness of

ANS:E - 25 mm

For determining the ultimate bearing capacity of soil using a load plate test, the recommended minimum thickness of the square bearing plate should be 25 mm. A thicker plate helps distribute the load more evenly and prevents the plate from deforming excessively during the test, ensuring more accurate results.