Two water pipes of diameters 2 cm and 4 cm are connected in series i.e end to end. The velocity of flow of water in the pipe of 2 cm diameter is :

Options

A. `4` times that of `Q`
B. `2` times that of `Q`
C. `1//2` times that of `Q`
D. `1//4` times that of `Q`

Answer

A

Explanation

by `A_(1)V_(1) = A_(2)V_(2)`
`((piD_(1)^(2))/(4))V_(1) = ((piD_(2)^(2))/(4))V_(2)`
`V_(2) = 4V_(1)`