An inverted U-tube manometer is used to measure the pressure difference between two pipes $A$ and $B$ ,as shown in figure.pipe $A$ is carrying oil (specific gravity$=0.8$ ) and pipe $B$ is carrying water.The densities of air and water are $1.16 kg/m^3$ and $1000\: kg/m^3$,respectively.The pressure difference between pipes $A$ and $B$ is ________$kPa$.
Acceleration due to gravity $g =10\:m/s^2$.
