Two pipes of radii $2 \, cm$ and $4 \, cm$ are connected in series. What is the ratio of the flow velocities of the fluid in these pipes?

Water is flowing through a tube of non-uniform cross-section. The ratio of the radius at the entry and exit end of the pipe is $3:2$. Then the ratio of velocities at the entry and exit of the liquid is:

In the figure shown,a liquid is flowing through a tube at the rate of $0.1\, m^3/sec$. The tube is branched into two semicircular tubes of cross-sectional area $A/3$ and $2A/3$. The velocity of liquid at $Q$ is ......... $m/sec$. (The cross-section of the main tube $= A = 10^{-2}\, m^2$ and $v_p = 20\, m/sec$)

What is the effect on the velocity of fluid if streamlines are widely spaced?

An engine pump ejects a liquid of density $\rho$ through a pipe of cross-sectional area $A$. If the velocity of the liquid coming out of the pipe is $v$,find the rate at which kinetic energy is imparted to the liquid.

An incompressible liquid flows through a horizontal tube as shown in the following figure. Then the velocity $v$ of the fluid is ....... $m/s$.