The ratio of hydraulic stress and volumetric strain is called _____.

The correct answer is Bulk modulus.

 Key Points

• Bulk modulus is the correct term for the ratio of hydraulic stress to volumetric strain.
• It quantifies the substance's resistance to uniform compression, a fundamental property in understanding how materials deform under stress.

Additional Information 

• Equivalence - This term does not directly relate to the concept of the ratio between hydraulic stress and volumetric strain. Equivalence generally refers to a state of being equal or equivalent in value, function, meaning, etc., but not in this specific physical context.
• Compression - While compression is related to the concept of applying stress and causing strain, it is a process or effect rather than a measure or ratio. Compression refers to the act of pressing together or the state of being compressed.
• Semi Modulus - This term is not standard in the context of material science or physics related to stress and strain. There isn't a defined physical quantity known as ""Semi modulus"" in the study of materials' responses to external forces. -
• Summary - Bulk modulus is the appropriate term for describing the ratio of hydraulic stress to volumetric strain, highlighting the material's resistance to compression. Other options either refer to different concepts or are not directly related to the specific ratio in question."