# GATE2015-3-9

Couette flow is characterized by

1. steady, incompressible, laminar flow through a straight circular pipe
2. fully developed turbulent flow through a straight circular pipe
3. steady, incompressible, laminar flow between two fixed parallel plates
4. steady, incompressible, laminar flow between one fixed plate and the other moving with a constant velocity

recategorized

## Related questions

A Prandtl tube (Pitot-static tube with $C$=$1$) is used to measure the velocity of water. The differential manometer reading is $10$ $mm$ of liquid column with a relative density of $10$. Assuming $g$ = $9.8$ $m$/$s^2$, the velocity of water (in $m/s$) is ________
A rigid container of volume $0.5 m^3$ contains $1.0$ kg of water at $12^\circ C$ $(v_f = 0.00106 m^3/kg$, $v_g= 0.8908 m^3/kg)$. The state of water is compressed liquid saturated liquid a mixture of saturated liquid and saturated vapor superheated vapor
Three parallel pipes connected at the two ends have flow-rates $Q_1$, $Q_2$ and $Q_3$ respectively, and the corresponding frictional head losses are $h_{L1}$, $h_{L2}$ and $h_{L3}$ respectively. The correct expressions for total flow rate $(Q)$ and frictional head loss across the two ends ($h_L$ ... $Q = Q_1 = Q_2 = Q_3; h_L = h_{L1} = h_{L2} = h_{L3}$
A two-dimensional incompressible frictionless flow field is given by $\overrightarrow{u} = x \hat{i} – y \hat{j}$. If $\rho$ is the density of the fluid, the expression for pressure gradient vector at any point in the flow field is given as $\rho(x \hat{i}+y \hat{j})$ $– \rho(x \hat{i}+y \hat{j})$ $\rho(x \hat{i} – y \hat{j})$ $– \rho(x^2 \hat{i}+y^2 \hat{j})$
For a hydrodynamically and thermally fully developed laminar flow through a circular pipe of constant cross-section, the Nusselt number at constant wall heat flux $(Nu_q)$ and that at constant wall temperature $(Nu_T)$ are related as $Nu_q > Nu_T$ $Nu_q < Nu_T$ $Nu_q = Nu_T$ $Nu_q = (Nu_T)^2$