Question

A capillary tube is attached horizontally to a constant heat arrangement. If the radius of the capillary tube is increased by 10%, then the rate of flow of liquid will change nearly by

• A. 0.1
• B. 0.46
• C. -0.1
• D. -0.4

Answer 1

Answer: (B)

0.46

Answer 2

Volume of liquid coming out of the tube per second $\Rightarrow V = \frac{ p p \pi r^4 }{ 8 \eta l }$ $\Rightarrow \frac{ V_2 }{ V_1 } = \bigg [ \frac{ r_2 }{ r_1 } \bigg ]^4$ $\Rightarrow V_2 = V_1 \bigg [\frac{ 110 }{ 100 } \bigg ]^4$ = $V_1 ( 1.1)^4 = 1.4641$volt $\Rightarrow \frac{ \triangle V }{ V }$ $= \frac{ V_2 - V_1 }{ V }$ $= \frac{ 1.464 1 - V }{ V }$ $= 46\%$