Here, `A= 800 cm^(2) ` ,
`F= mg = (12 xx 1000 xx 980) dyn es`.
Thus, pressure on the liquid,
`p= F/A = (12 xx 1000 xx 980)/(800) dyn e//cm^(2)`
If h is the difference in level of liquid in the two tubes then,
`p = h rho g = hxx 1 xx 980`
`:. h xx 1 xx 980 = (12 xx10 xx 980)/(800)`
or, ` h=15.0 cm`.