The figure shows a glass tube (linear co-efficient of expansion is α) completely filled with a liquid of volume expansion co-efficient γ. On heating length of the liquid column does not change. Choose the correct relation between γ and α

When length of the liquid column remains constant, then the level of liquid moves down with respect to the container, thus γ must be less than 3α.Now we can write V=V0(1+γΔT)Since V=Al0=A0(1+2αΔT)l0=V0(1+2αΔT)Hence V0(1+γΔT)=V0(1+2αΔT)⇒γ=2α