Question

Which of the following is true for bulk modulus of elasticity?
A) It is the ratio of compressive stress to volumetric strain
B) It is the ratio of compressive stress to the linear strain
C) It is the ratio of tensile stress to volumetric strain
D) It is the ratio of tensile stress to linear strain

Answer 1

Hint
Bulk modulus is defined as the ratio of hydraulic stress to hydraulic strain.it can be expressed as $B = \dfrac{{ - P}}{{\dfrac{{\Delta V}}{V}}}$

Complete step-by-step answer:
We have already known that and have seen that when the body is immersed in a fluid, it undergoes hydraulic stress, which is equal in magnitude to hydraulic pressure. The same leads to the decrease in the volume of the body and produces a strain that produces volumetric strain.
Bulk Modulus is related to the compression of a liquid and the decrease in volume per unit volume. It is the ratio of compressive stress to the volumetric strain.
It is expressed as $B = \dfrac{{ - P}}{{\dfrac{{\Delta V}}{V}}}$
Negative sign indicates that when the pressure increases then volume decreases or vice versa. To be specific if pressure P is positive then change in volume is negative. Hence for a system in equilibrium
The value of bulk modulus B is always positive. The S.I. The unit of bulk modulus is the same as that of pressure that is $\dfrac{N}{m^2}$ or Pa.
Hence, option (A) is correct.

Additional Information
The reciprocal of bulk modulus is known as the compressibility and it is denoted by K, It is defined as the fractional change in volume per unit increase in pressure.

Note
Bulk modulus for solids are much larger than liquids, which are again larger than the bulk modulus for gases. Hence solid bodies are most compressible and gases are least compressible