Two capillary tubes of lengths in the ratio 2 : 1 and radii in the ratio 1 : 2 are connected in series. Assume the flow of the liquid through the tube is steady. Then, the ratio of pressure difference accros the tubes is

Question

$\begin {array} {1 1} (1)\;1 : 8 & \quad (2)\; 1 : 16 \\ (3)\;32 : 1 & \quad (4)\;1 : 1 \end {array}$