Two capillary tubes of same length and radii in the ration 1:2 are connected in series and a liquid flows through this system understreamline conditions. if the pressure across the two extreme ends of the tube system is 1m of water then what is the pressure difference across the first capillary?
1Poiseuille's Equation is to be used .. wait yaar i am typing the solution ..
1Δp / (μL/8πr4) = Q : flow rate which is constant ...this is the general equation ..
and the two pipes are connected in series ..
so
Δp / (μL/8πr4 + μL/8π(2r)4) = Q'
→ Δp / (17 μL/8π(2r)4) = Q'
this is same across the first tube so
Δp / (17 μL/8π(2r)4) = Δp' /( μL/8πr4)
Δp' = 16/17 Δp
so the answer is pressure across the 1st tube is 16/17 m of water
