Question

How much pressure should be applied on a litre of water if it is to be compressed by $0.1\%$ ?
(Bulk modulus of water = $2100 \,MPa)$

• A. $2100 \, kpa$
• B. $210 \, kpa$
• C. $2100\, Mpa$
• D. $210\, Mpa$

Answer 1

Answer: (A)

Here, $V=1 \, litre=10^{-3} m^{3}$,
$B=2100 \,Mpa$ $=2100\times10^{6} \,pa$
Volume strain$=\frac{\Delta V}{V}$ $=\frac{0.1}{100}$ $=1\times10^{-3}$
Bulk modulus,$B=\frac{P}{\Delta V/ V}$
$P=B \frac{\Delta V}{V}$ $=2100\times10^{6}\times1\times10^{-3}$
$=21\times10^{5} \,pa$ $=2100\times10^{3}\,pa$ $=2100\, kpa$