GATE Overflow for GATE XE - Recent activity in Flow and Fluid Properties

Answer reshown: GATE XE 2022 | Question: 15

Thu, 21 May 2026 09:57:47 +0000

Option C , Since dynamic viscoscity doen't depent on temperature.It realted with velocity gradient (Rate of shear strain ) and the shear stress

Edited: GATE XE 2026 | Question: 152

Thu, 02 Apr 2026 10:25:56 +0000

The mass (in $\mathrm{kg}$) of dry air in a room, measuring $10 m \times 7 m \times 3 m$, is $\_\_\_\_$. (rounded off to two decimal places)

[Density of dry air is $1.029 \times 10^{-3} \mathrm{~g} \mathrm{~cm}^{-3}$]

Edited: GATE XE 2026 | Question: 149

Thu, 02 Apr 2026 10:22:55 +0000

In a stable atmosphere, the change in pressure (in kilo Pascal) at a height of $100 \mathrm{~m}$ from the mean sea level is $\_\_\_\_$. (rounded off to three decimal places)

[Density of air is $1.029 \mathrm{~kg} \mathrm{~m}^{-3}$ and acceleration due to gravity is $9.81 \mathrm{~m} \mathrm{~s}^{-2}$]

Edited: GATE XE 2026 | Question: 30

Tue, 31 Mar 2026 07:57:08 +0000

A rectangular block (density $=600 \mathrm{~kg} \cdot \mathrm{~m}^{-3}$ ) with base area of $0.06 \mathrm{~m}^{2}$ and height $15$ cm is partially submerged in water (density $=1000 \mathrm{~kg} \cdot \mathrm{~m}^{-3}$), as shown in the figure. Assume acceleration due to gravity as $10 \mathrm{~m}. \mathrm{s}^{-2}$. The submerged depth, $h$ (in $\mathrm{m}$) of the block in the water is $\_\_\_\_$. (rounded off to two decimal places)

Edited: GATE XE 2026 | Question: 28

Tue, 31 Mar 2026 07:54:54 +0000

A gas is pressurized in a vertical frictionless piston-cylinder device, as shown in the figure. The piston has a mass of $4$ kg and a cross-sectional area of $40 \mathrm{~cm}^{2}$. A metallic block of $13$ kg is placed on the piston. The atmospheric pressure ( $p_{a}$ ) is $1$ bar. Assume acceleration due to gravity as $10 \mathrm{~m} . \mathrm{s}^{-2}$. The pressure inside the cylinder, $p_{i}$ (in bar) is $\_\_\_\_$ . (rounded off to three decimal places)

Edited: GATE XE 2026 | Question: 16

Sat, 28 Mar 2026 10:36:41 +0000

Consider the following statements:

Assertion (a)

Surface tension acts along the interface of two fluids.

Reason (r)

The pressure of the fluid inside a bubble is higher than that of the fluid outside the bubble.

Which one of the following options is correct?

Both (a) and (r) are true, and (r) is the correct explanation of (a).
Both (a) and (r) are true, however (r) is not the correct explanation of (a).
(a) is true, but (r) is false.
(a) is false, but (r) is true.

Edited: GATE XE 2025 | Question: 172

Mon, 30 Jun 2025 16:28:12 +0000

A floating hot air balloon with volume $1000 \mathrm{~m}^{3}$ and gross mass (excluding the air in the balloon) $100 \: \mathrm{kg}$ is in hydrostatic balance where the external air temperature is $10^{\circ} \mathrm{C}$ and density is $1 \mathrm{~kg} \mathrm{~m}^{-3}$. The temperature of the air inside the balloon is $\_\_\_\_\_\_$ ${ }^{\circ} \mathrm{C}$. (Round off to the nearest integer.)

Edited: GATE XE 2025 | Question: 39

Sun, 29 Jun 2025 12:51:30 +0000

Consider, a kite weighing $100$ grams as essentially a rigid flat plate making an angle $8^{\circ}$ with the horizontal and having a planform area of $0.045 \mathrm{~m}^{2}$ when exposed to horizontal parallel wind of $60 \mathrm{~km} / \mathrm{h}$. The thread string of the kite makes an angle $45^{\circ}$ with the horizontal. A tension of $450$ grams in the thread is necessary to float the kite steadily. Take air density as $1.2 \mathrm{~kg} / \mathrm{m}^{3}$ and gravitational acceleration as $9.81 \mathrm{~m} / \mathrm{s}^{2}$. The lift coefficient $\left(C_{L}\right)$ associated with the air flow around steadily floating kite (rounded off to $2$ decimal places) is $\_\_\_\_\_\_$

Edited: GATE XE 2025 | Question: 33

Sun, 29 Jun 2025 12:44:37 +0000

A solid body of uniform specific gravity floats in a deep liquid pool. Take $B, G$, and $M$ as the centre of buoyancy, centre of gravity, and metacentre of the body, respectively.

Which one of the following options is correct for the stable floatation of the body in the pool when the body is given a small tilt angle?

$\overline{M G}$ is the metacentric height and $G$ should lie below $M$
$\overline{M G}$ is the metacentric height and $B$ should lie above $M$
$\overline{M B}$ is the metacentric height and $B$ should lie below $M$
$\overline{M B}$ is the metacentric height and $G$ should lie above $M$

Edited: GATE XE 2025 | Question: 26

Sun, 29 Jun 2025 12:32:06 +0000

For a steady and incompressible flow, the velocity field $(\vec{V})$ in Cartesian $(x, y, z)$ coordinate system is given as:

$$\vec{V}=5 x i-P y j+3 k$$

Here, $i, j$, and $k$ are unit vectors along $x, y$, and $z$ directions, respectively and $P$ is a constant.

Which one of the following options is the correct value of $P$ that satisfies the conservation of mass for the given velocity field?

$5$
$-5$
$8$
$2$

Recategorized: GATE XE 2024 | Question: 12

Mon, 05 May 2025 14:41:07 +0000

Which one of the following figures shows the CORRECT dependence of apparent viscosity $(\eta)$ on rate of shear strain $(d u / d y)$ for pseudoplastic fluids?

Recategorized: GATE XE 2024 | Question: 19

Mon, 05 May 2025 14:40:48 +0000

For an immersed neutrally buoyant body to be in stable equilibrium, the center of gravity of the body is directly

above the metacenter.
below the metacenter.
above the center of buoyancy.
below the center of buoyancy.

Recategorized: GATE XE 2024 | Question: 24

Mon, 05 May 2025 14:40:31 +0000

Consider a fluid flow around an airfoil as shown in figure.

The directions of drag force and lift force, respectively are along

OA and OC.
OA and OD.
OB and OC .
OB and OD .

Recategorized: GATE XE 2024 | Question: 25

Mon, 05 May 2025 14:40:28 +0000

A vessel which contains a volatile liquid and its vapour is connected with a mercury manometer as shown in figure. Both the liquid and vapour phases are at equilibrium. The vapour pressure and density of the volatile liquid are $107.6$ kPa and $700 \mathrm{~kg} / \mathrm{m}^{3}$, respectively. The density of the mercury is $13600 \mathrm{~kg} / \mathrm{m}^{3}$. Acceleration due to gravity $(\mathrm{g})$ is $10 \mathrm{~m} / \mathrm{s}^{2}$ and atmospheric pressure is $101$ kPa . Hydrostatic pressure created by the weight of the vapour is neglected.

The height, $h$ $\text{(in m , rounded off to two decimal places)}$ of the mercury column in figure is ____________.

Recategorized: GATE XE 2024 | Question: 27

Mon, 05 May 2025 14:40:19 +0000

Consider two parallel plates separated by a distance of $1$ cm filled with a Newtonian fluid of viscosity $10^{-3} \mathrm{~Pa}$.s. The top plate is moving with a velocity of $1 \mathrm{~m} / \mathrm{s}$ whereas the bottom plate is stationary. The shear stress $\text{(in Pa , rounded off to one decimal place)}$ on the top plate is __________.

Recategorized: GATE XE 2022 | Question: 12

Mon, 05 May 2025 12:43:57 +0000

A heavy horizontal cylinder of diameter $D$ supports a mass of liquid having density $\rho$ as shown in the figure. Find out the vertical component of force exerted by the liquid per unit length of the cylinder if $g$ is the acceleration due to gravity.

$\frac{\pi D^{2}}{4} \rho g$
$\frac{\pi D^{2}}{8} \rho g$
$\frac{\pi D^{2}}{2} \rho g$
$\frac{\pi D^{2}}{3} \rho g$

Recategorized: GATE XE 2022 | Question: 30

Mon, 05 May 2025 12:43:07 +0000

A wooden cylinder $\text{(specific gravity} $=0.6$)$ of length $L$ and diameter $D$ floats in water $\text{(density}$ $1000 \mathrm{~kg} / \mathrm{m}^3)$. Find out the minimum value of $D / L$ for which the cylinder floats with its axis vertical.
$\text{(Round off to three decimal places)}$

Recategorized: GATE XE 2022 | Question: 31

Mon, 05 May 2025 12:43:01 +0000

A wooden cylinder $\text{(specific gravity}$ $=0.6$ ) of length $L$ and diameter $D$ floats in water $\text{(density}$ $1000 \mathrm{~kg} / \mathrm{m}^3$). Find out the minimum value of $D / L$ for which the cylinder floats with its axis vertical.
$\text{(Round off to three decimal places)}$

Recategorized: GATE XE 2023 | Question: 15

Mon, 05 May 2025 12:21:39 +0000

Among the shear stress versus shear strain rate curves shown in the figure, which one corresponds to a shear thinning fluid ?

$\mathrm{P}$
$\mathrm{Q}$
$\mathrm{R}$
$\mathrm{S}$

Recategorized: GATE XE 2023 | Question: 18

Mon, 05 May 2025 12:21:29 +0000

Which of the following statements are true?

$\text{(i)}$ Conservation of mass for an unsteady incompressible flow can be represented as $\nabla \cdot \vec{V}=0$, where $\vec{V}$ denotes velocity vector.
$\text{(ii)}$ Circulation is defined as the line integral of vorticity about a closed curve.
$\text{(iii)}$ For some fluids, shear stress can be a nonlinear function of the shear strain rate.
$\text{(iv)}$ Integration of the Bernoulli's equation along a streamline under steady-state leads to the Euler's equation.

$\text{(ii) and (iv)}$ only
$\text{(i), (ii) and (iii)}$ only
$\text{(i) and (iii)}$ only
$\text{(ii) and (iv)}$ only

Recategorized: GATE XE 2023 | Question: 20

Mon, 05 May 2025 12:21:25 +0000

A stationary object is fully submerged in a static fluid, as shown in the figure. Here, $\text{CG}$ and $\mathrm{CB}$ stand for center of gravity and center of buoyancy, respectively. Which one(s) among the following statements is/are true?

The object is in stable equilibrium if $y_{C G}>y_{C B}$.
The object is in stable equilibrium if $y_{C G}$
The object is in neutral equilibrium if $y_{C G}=y_{C B}$.
The object is in unstable equilibrium if $y_{C G}=y_{C B}$.

Recategorized: GATE XE 2023 | Question: 27

Mon, 05 May 2025 12:21:00 +0000

\begin{tabular}{|l}
Q. 37 \\
Water $\left(\right.$ density $\left.=1000 \mathrm{~kg} / \mathrm{m}^{3}\right)$ and alcohol (specific gravity $=0.7$ ) enter a \\
Y-shaped channel at flow rates of $0.2 \mathrm{~m}^{3} / \mathrm{s}$ and $0.3 \mathrm{~m}^{3} / \mathrm{s}$, respectively. Their \\
mixture leaves through the other end of the channel, as shown in the figure. The \\
average density $\left(\right.$ in $\left.\mathrm{kg} / \mathrm{m}^{3}\right)$ of the mixture is
\end{tabular}

Recategorized: GATE XE 2023 | Question: 33

Mon, 05 May 2025 12:20:43 +0000

Q. 43 A stationary circular pipe of radius $R=0.5 \mathrm{~m}$ is half filled with water (density =
$1000 \mathrm{~kg} / \mathrm{m}^{3}$ ), whereas the upper half is filled with air at atmospheric pressure, as
shown in the figure. Acceleration due to gravity is $g=9.81 \mathrm{~m} / \mathrm{s}^{2}$. The magnitude
of the force per unit length (in $\mathrm{kN} / \mathrm{m}$, rounded off to one decimal place) applied by
water on the pipe section $\mathrm{AB}$ is

Recategorized: GATE XE 2023 | Question: 83

Mon, 05 May 2025 12:18:05 +0000

\begin{tabular}{|l|l|}
\hline Q.93 & Adiabatic bulk modulus of a substance is defined as \\
\hline

& $-\frac{1}{v}\left(\frac{\partial v}{\partial P}\right)_{T}$ \\
\hline
& $-v\left(\frac{\partial P}{\partial v}\right)_{T}$ \\
\hline
& $-\frac{1}{v}\left(\frac{\partial v}{\partial P}\right)_{S}$ \\
\hline
& $-v\left(\frac{\partial P}{\partial v}\right)_{S}$
\end{tabular}

Recategorized: GATE XE 2023 | Question: 162

Mon, 05 May 2025 12:13:56 +0000

Q. 172
A cylindrical tank containing water is rotating about the z-axis at a constant angular velocity of $10 \mathrm{rad} \mathrm{s}^{-1}$. The schematic of the isobaric surface is shown in the following illustration, where ' $\mathrm{A}$ ' and ' $\mathrm{B}$ ' are two points on the isobaric surface at heights ' $z_{1}$ ' and ' $z_{2}$ ', respectively. Assuming the atmospheric pressure to be negligible and no transient flow, estimate the elevation difference in $\mathrm{m}$ between ' $\mathrm{z}_{1}$ ' and ' $\mathrm{z}_{2}$ '.
(consider $\mathrm{r}_{1}=0.5 \mathrm{~m}, \mathrm{r}_{2}=1.0 \mathrm{~m}$ and gravitational acceleration $g=9.8 \mathrm{~m} \mathrm{~s}^{-2}$, rounded off to two decimal places)

Recategorized: GATE XE 2024 | Question: 147

Mon, 05 May 2025 10:52:39 +0000

If the isobars and isopycnals are parallel to each other, the flow is said to be

baroclinic
barotropic
geostrophic
rotational