Question: Dimensional formula for volume elasticity is: [PMT/NEET-1991]
a. $M^{1}L^{2}T^{-2}$
b. $M^{1}L^{-3}T^{-2}$
c. $M^{1}L^{2}T^{-2}$
d. $M^{1}L^{-1}T^{-2}$

Solution
Volume (bulk) elasticity $E = \dfrac{\text{Stress}}{\text{Strain}}$.

• Strain is dimensionless.
• Stress = Pressure = Force/Area = $\dfrac{MLT^{-2}}{L^{2}} = ML^{-1}T^{-2}$.

So,
$
[E] = ML^{-1}T^{-2}
$

Answer
d. $M^{1}L^{-1}T^{-2}$