Explain Bulk Modulus.

Explanation

When a body is submerged in a fluid, it undergoes a hydraulic stress (equal in magnitude to the hydraulic pressure). This leads to the decrease in the voume of the body thus producing strain called volume strain.
The ratio of hydraulic stress to the corresponding hydraulic strain is called bulk modulus. It is denoted by symbol B.
`therefore B = (-p)/((Delta V//V))`
The negative sign indicates that with an increases in pressure, a decrease in volume occurs. That is if p is positive, `Delta V` is negative.
Thus, for a system in equilibrium, the vlaue of bulk modulus B is always positive.
SI unit of bulk modulus is the same as that pressure. Means `Nm^(-2)` or Pa and dimensional formula is `[M^(1) L^(-1) T ^(-2)].`
Stress, strain and various elastic moduli:
Hence, compressibility of solid is very low, while gases have the most compressibility.
Gases are ten lakh time more compressible compare to solids compressibility of gases are very large. It will be changes with temperature and pressure.
Incompressibility of solid mainly is due to firm bonding of neighbour atoms.
Atoms of liquid is also bonded to neighbour atoms but, it is less compare to in solid.
Atoms of goposses weak bonding to their neighbouring atoms.
Bulk moduli (B) of some common materials :