Question

An ideal fluid flows through a pipe of circular cross-section made of two sections with diameters `2.5 cm` and `3.75 cm`. The ratio of the velocities in the two pipes is
A. `9:4`
B. `3:2`
C. `sqrt(3):sqrt(2)`
D. `sqrt(2):sqrt(3)`

Answer 1

Correct Answer - A
According to equation of continuity
`a_(1)v_(1)=a_(2)v_(2)`
or `(v_(1))/(v_(2))=(a_(2))/(a_(1))=(pid_(2)^(2)//4)/(pid_(1)^(2)//4)=((d_(2))/(d_(1)))^(2)=((3.75)/(2.50))^(2)=(9)/(4)`