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GATE-2018
Q: For a two-dimensional incompressible flow field given by u=A(xi −yj ), where A>0 , which one of the following statements is FALSE?
Q: For a two-dimensional incompressible flow field given by u=A(xi −yj ), where A>0 , which one of the following statements is FALSE?
where u,i,j are vectors.
- A: It satisfies continuity equation.
- B: It is unidirectional when x→0 and y→∞.
- C: Its streamlines are given by x=y.
- D: It is irrotational.
GATE-2018
Q: A tank open at the top with a water level of 1 m, as shown in the figure, has a hole at a height of 0.5 m. A free jet leaves horizontally from the smooth hole. The distance X (in m) where the jet strikes the floor is
- A: 0.5
- B: 1
- C: 2
- D: 4
GATE-2018
Q: The viscous laminar flow of air over a flat plate results in the formation of a boundary layer. The boundary layer thickness at the end of the plate of length L is δL. When the plate length is increased to twice its original length, the percentage change in laminar boundary layer thickness at the end of the plate (with respect to δL) is ________ (correct to two decimal places).
GATE-2017
Q: For steady flow of a viscos incompressible fluid through a circular pipe of constant diameter, the averavge velocity in the fully developed region is constant. Which one of the following statements about the average velocity in the developing region is TRUE?
- A: It increases until the flow is fully developed.
- B: It is constant and is equal to the average velocity in the fully developed region.
- C: It decreases until the flow is fully developed.
- D: It is constant but is always lower than the average velocity in the fully developed region.
GATE-2017
Q: Consider steady flow of an incomressible fluid through two long and straight pipes of diameters d1 and d2 arranged in series. Both pipes are of equal length and the flow is turbulent in both pipes. The friction factor for turbulent flow though pipes is of the form, f=K(Re)−n, where K and n are known positive constants and Re is the Reynolds number. Neglecting minir losses, the ratio of the frictional pressure drop in pipe 1 to that in pipe 2, (△P1/△P2), is given by
- A: (d2/d1)(5−n)
- B: (d2/d1)5
- C: (d2/d1)(3−n)
- D: (d2/d1)(5+n)
GATE-2017
Q: For the stability of a floating body the
- A: centre of buoyancy must coincide with the centre of gravity
- B: centre of buoyancy must be above the centre of gravity
- C: centreof gravity must be above the centre of buoyancy
- D: metacentre must be above the centre of gravity
GATE-2017
Q: A 60 mm-diameter water jet strikes a plate containing a hole of 40 mm diameter as shown in the figure. Part of the jet passes through the hole horizontally, and the remaining is deflected vertically. The density of water is 1000 kg/m3. If velocities are as indicates in the figure, the magnitude of horizontal force (in N) required to hold the plate is_______
GATE-2017
Q: For a laminar flow of water over a sphere, the drag coefficient CF is defined as CF=F/(ρU2D2) , where F is the drag force, ρ is the fluid density, U is the fluid velocity and D is the diameter of the sphere. The density of water is 1000 kg/m3. The diameter of the sphere is 100 mm and the velocity is 2 m/s, the drag coefficient is 0.5. If water now flows over another sphere of diameter 200 mm under dynamically similar conditions, the drag force (in N) on the sphere is___________
GATE-2016
Q: For a floating body, buoyant force acts at the
- A: centroid of the floating body
- B: center of gravity of the body
- C: centroid of the fluid vertically below the body
- D: centroid of the displaced fluid
GATE-2016