Let the difference between \(2 \operatorname{limbs}\) be \(x\)
Pressure on the line \(Y Y\) should be same below both limbs, so
\(\rho_{\text {glycerine }} \times g \times h=\rho_{\text {water }} \times g \times(h+x)\)
\(\Rightarrow 1.2 \times 10=1 \times(h+x)\)
\(\Rightarrow 2 \,cm =x\)