Question

The Bulk modulus for an incompressible liquid is:

• A. Zero
• B. unity
• C. Infinity
• D. between 0 and 1

Answer 1

Answer: (C)

Since liquid is incompressible there is no charge in volume.
When strain is small the ratio of the normal stress to the volume strain is called the bulk modulus of material of the body.
$\therefore B=\frac{\text{ normal stress }}{\text{ volume strain }}$
$=\frac{\text{ normal stress }}{\text{ Change in volume/original volume }}$
Since, the liquid is incompressible change in volume is zero.
$\therefore B=\frac{\text{ normal stress }}{0}=\infty$
Hence, bulk modulus is infinite.