Question

The pressure of a liquid of liquid of density $1g/c{m}^3$ at a depth 2 cm from the surface of liquid is(atmospheric pressure=$1\times {10}^5$ Pa and g=10m/s).

• A. $1.002\times {10}^5$ Pa
• B. $1.004\times {10}^5$ Pa
• C. $1.002\times {10}^4$ Pa
• D. $1.02\times {10}^5$ Pa

Answer 1

The correct option is A $1.002\times {10}^5$ Pa

Density of liquid:

$\begin{array}{c}\rho =1g/cc\\ =1000\frac{kg}{m^3}\\ Depth:\\ h=2cm\\ =0.02m\end{array}$

Absolute pressure at a given depth:

$\begin{array}{c}P=P_0+\rho gh\\ =1\times {10}^5+\left[1000\right]\left[10\right]\left[0.02\right]\\ =100200Pa\end{array}$

Gauge pressure is given depth:

$\begin{array}{c}P=P_0+\rho gh\\ =\left[1000\right]\left[10\right]\left[0.02\right]\\ =200Pa\end{array}$