Q. If the volume of a block of aluminium is decreased by 1%, the pressure (stress) on its surface is increased by (Bulk modulus of $A1 = 7.5 \times 10^{10}{Nm}^{- 2})$
A) $7.5 \times 10^{10}{Nm}^{- 2}$
B) $7.5 \times 10^{8}{Nm}^{- 2}$
C) $7.5 \times 10^{6}{Nm}^{- 2}$
D) $7.5 \times 10^{4}{Nm}^{- 2}$
Explanation
(b) Given $\frac{\mathrm{\Delta}V}{V} \times 100 = 1\% = \frac{1}{100}$
Bulk modulus,
$B = \frac{P}{\frac{\mathrm{\Delta}V}{V}} = \frac{pV}{\mathrm{\Delta}V}$
or $p = \frac{B\mathrm{\Delta}V}{V} = 7.5 \times 10^{10} \times \frac{1}{100}$
$= 7.5 \times 10^{8}{Nm}^{- 2}$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.