Question

The area of cross-section of the wider tube shown in figure is $800c{m}^2$. If a mass of 12 kg is placed on the massless piston, the difference in heights h in the level of water in the two tubes is :

• A. 10 cm
• B. 6 cm
• C. 15 cm
• D. 2 cm

Answer 1

The correct option is C 15 cm

Given,

$m=12kg=12000g$

$g=980g/c{m}^2$

$A=800c{m}^2$

$\rho =1g/c{m}^3$

Pressure, $P=\rho gh=\frac{mg}{A}$

$1\times 980\times h=\frac{12\times 1000\times 980}{800}$

$h=\frac{12\times 10}{8}=15cm$

The correct option is C.