Question

A capillary tube is attached horizontally to a constant pressure head arrangement. If the radius of the capillary tube is increased by `10%`, then the rate of flow of the liquid shall change nearly by
A. `+10%`
B. `+46%`
C. `-10%`
D. `-40%`

Answer 1

Correct Answer - B
Volume of liquid coming out of the tube per second,
`V=(ppir^(4))/(8etal)impliesV_(2)/(V_(1))=((r_(2))/(r_(1)))^(4)`
`implies V_(2)=V_(1)((110)/(100))^(4)=V_(1)(1.1)^(4)=1.4641V_(1)"unit"`
`implies(DeltaV)/(V_(1))=(V_(2)-V_(1))/(V_(1))=(1.4641V_(1)-V_(1))/V_(1)~=46%`