$CU$ test is performed on a clay specimen. The soil sample is first consolidated a confining pressure of $50k\frac{N}{m^2}$ then applied with deviatoric stress under drain condition. At failure the deviatoric stress is $38k\frac{N}{m^2}$ and the excess water pressure is $36k\frac{N}{m^2}.$

What is A coefficient? Is this clay a OC or NC clay? Please explain.

What is $($undrain$)?$

What is ${}^{\text{'}}($drain$)?$

What is the angle of failure plane?

What is the ${}^{\text{'}}$ and $$ on the failure plane?

If a test is performed on the same specimen, what is the deviatoric stress at the given confining stress of $50k\frac{N}{m^2}?$