Fluid Mechanics GATE Questions

A highly popular method used to prepare for the GATE Exam is to sincerely practise all the previous years’ GATE Questions. Candidates can practise, analyse and understand concepts while solving them. It will also help you strengthen your time management skills. We have attempted to compile, here in this article, a collection of GATE Questions on Fluid Mechanics.

Candidates are urged to practise these Fluid Mechanics GATE previous year questions to get the best results. Fluid Mechanics is an important topic in the GATE ME question paper, and solving these questions will help the candidates to prepare more proficiently for the GATE exams. Meanwhile, candidates can find the GATE Questions for Fluid Mechanics here, in this article below, to solve and practise before the exams. They can also refer to these GATE
previous year question papers and start preparing for the exams.

GATE Questions on Fluid Mechanics

1. Assuming constant temperature condition and air to be an ideal gas, the variation in atmospheric pressure with height calculated from fluid statics is

(GATE ME 2016 Set 2)

1. Linear
2. Exponential
3. Quadratic
4. Cubic

Answer (b)

2. For a Newtonian fluid:

(GATE ME 2006)

1. Shear stress is proportional to shear strain
2. Rate of shear stress is proportional to shear strain
3. Shear stress is proportional to rate of shear strain
4. Rate of shear stress is proportional to rate of shear strain

Answer (c)

3. An incompressible fluid (kinematic viscosity x
   \(\begin{array}{l}10^{-7} m^{2}/s\end{array} \)
   , specific gravity, 0.88) is held between two parallel plates. If the top plate is moved with a velocity of while the bottom one is held stationary, the fluid attains a linear velocity profile in the gap of between these plates; the shear stress in Pascal on the surface of bottom plate is:

(GATE ME 2004)

1. 65.1
2. 0.651
3. 6.51
4. 651

Answer (b)

4. The difference in pressure (in
   \(\begin{array}{l}N/m^{2}\end{array} \)
   ) across an air bubble of diameter 0.001 immersed in water (surface tension ) is _____________

(GATE ME 2014 Set 2)

1. Between 287 and 289
2. Between 280 and 284
3. Between 290 and 295
4. Between 281 and 283

Answer (a)

5. The SI unit of kinematic viscosity (υ) is

(GATE ME 2001)

1. \(\begin{array}{l}m^{2}/s\end{array} \)
2. \(\begin{array}{l}m/s^{2}\end{array} \)
3. \(\begin{array}{l}m^{3}/s^{2}\end{array} \)

Answer (a)

6. Kinematic viscosity of air at
   \(\begin{array}{l}20^{0}C\end{array} \)
   is given to be x
   \(\begin{array}{l}10^{-5} m^{2}s\end{array} \)
   . Its kinematic viscosity at will be varying approximately:

(GATE ME 1999)

1. x
   \(\begin{array}{l}10^{-5}m^{2/s}\end{array} \)
2. x
   \(\begin{array}{l}10^{-5}m^{2/s}\end{array} \)
3. x
   \(\begin{array}{l}10^{-5}m^{2/s}\end{array} \)
4. x
   \(\begin{array}{l}10^{-5}m^{2/s}\end{array} \)

Answer (a)

7. If ′P′ is the gauge pressure within a spherical droplet, then gauge pressure within a bubble of the same fluid and of same size will be:

(GATE ME 1999)

1. \(\begin{array}{l}\frac{P}{4}\end{array} \)
2. \(\begin{array}{l}\frac{P}{2}\end{array} \)
3. P
4. 2P

Answer (d)

8. The dimension of surface tension is:

(GATE ME 1997)

1. \(\begin{array}{l}N/m^{2}\end{array} \)
2. \(\begin{array}{l}J/m^{2}\end{array} \)

Answer (c)

9. Within a boundary layer for a steady incompressible flow, the Bernoulli equation

(GATE ME 2015 Set 2)

1. Holds because the flow is steady
2. Holds because the flow is incompressible
3. Holds because the flow is transitional
4. Does not hold because the flow is frictional

Answer (d)

10. Consider an incompressible laminar boundary layer flow over a flat plate of length aligned with the direction of an incoming uniform free stream. If is the ratio of the drag force on the front half of the plate to the drag force on the rear half, then

(GATE ME 2007)

1. \(\begin{array}{l}F< \frac{1}{2}\end{array} \)
2. \(\begin{array}{l}F= \frac{1}{2}\end{array} \)
3. \(\begin{array}{l}F> 1\end{array} \)

Answer (d)

11. If is the distance measured from the leading edge of a flat plate, the laminar boundary layer thickness varies as

(GATE ME 2002)

1. \(\begin{array}{l}\frac{1}{x}\end{array} \)
2. \(\begin{array}{l}x^{4/5}\end{array} \)
3. \(\begin{array}{l}x^{2}\end{array} \)
4. \(\begin{array}{l}x^{1/2}\end{array} \)

Answer (d)

12. Flow separation in flow past a solid object is caused by

(GATE ME 2002)

1. A reduction of pressure to vapour pressure
2. A negative pressure gradient
3. A positive pressure gradient
4. The boundary layer thickness reducing to zero

Answer (c)

13. Navier Stokes equation represents the conservation of

(GATE ME 2000)

1. Energy
2. Mass
3. Pressure
4. Momentum

Answer (d)

14. For steady flow of a viscous incompressible fluid through a circular pipe of constant diameter, the average velocity in the fully developed region is constant. Which one of the following statements about the average velocity in the developing region is TRUE?

(GATE ME 2017 Set 1)

1. It increases until the flow is developed
2. It is constant and is equal to the average velocity in the fully developed region
3. It decreases until the flow is fully developed
4. It is constant but always lower than the average velocity in the fully developed region

Answer (b)

15. Couette flow is characterised by

(GATE ME 2015 Set 3)

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

Answer (d)