Correct Answer - (i) 0.54 cm of water column; (ii) 14.46 cm of water column
Rate of flow of liquid through each tube in series will be the same. If h is the height of the water column at the junction of two tubes in series, then `V = (pi xx (15- h)rho gxxr_1^4)/(8 eta l_1) = (pi (h rho g)xxr_2^4)/(8eta l_2)`
`or (15 - h)(r_1^4)/(l_1) = (hxxr_2^4)/(l_2)`
`or (15-h) ((0.06)^4)/(15)= (hxx(0.02)^2)/(5)`
On solving, h = 14.46 cm. :. Pressure difference across first tube = 15 - 14.46 = 0.56 cm of water column Pressure difference across second tube = 14.46 cm of water column