Question

An increase in pressure required to decrease the $200$ litres volume of a liquid by $0.004 \%$ in pipa is
(Bulk modulus of the liquid $=2100 \,Mpa$ )

• A. 188 kPa
• B. 8.4 kPa
• C. 18.8 kPa
• D. 84 kPa

Answer 1

Answer: (D)

Bulk modulus is given by
$K=\frac{\Delta P}{\Delta V / V}$
Given : $K=2100 \times 10^{6} \,Pa \,V=200$ lit.
$\Delta V=200 \times \frac{0.004}{100}=0.008$ lit
Putting the given values in eq (i)
$2100 \times 10^{6}=\frac{\Delta P}{0.008 / 200}$
so, $\Delta P =\frac{2100 \times 10^{6} \times 0.008}{200}$
$=84000\, Pa =84 \times 10^{3} $
$=84 \,kPa$