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Fluid Mechanics and Mechanical Operations

35 Questions
GATE→2026→Fluid Mechanics and Mechanical Operations→Fluid Mechanics and Mechanical Operations
Q1
MCQ[1 Mark]
Which one of the following is NOT a type of chain conveyor?
GATE→2026→Fluid Mechanics and Mechanical Operations→Fluid Mechanics and Mechanical Operations
Q2
MCQ[1 Mark]
Which one of the following ratios does Grashof number represent?
GATE→2026→Fluid Mechanics and Mechanical Operations→Fluid Mechanics and Mechanical Operations
Q3
MSQ[1 Mark]
In which of the following condition(s), Bernoulli's equation is applicable?
GATE→2026→Fluid Mechanics and Mechanical Operations→Fluid Mechanics and Mechanical Operations
Q4
NAT[1 Mark]
Consider two successive screen sizes in the Tyler standard screen scale, viz. 150 meshes per inch and 200 meshes per inch. Their linear sizes of the openings are L150L_{150} and L200L_{200}, respectively. If the value of L200L_{200} is 2.9×10−32.9 \times 10^{-3} inch, then the value of L150L_{150} (in inch) is ______ (rounded off to one decimal place).
GATE→2026→Fluid Mechanics and Mechanical Operations→Fluid Mechanics and Mechanical Operations
Q5
NAT[1 Mark]
Water is discharged from vertical side of a tank through a circular orifice of diameter 2 cm under laminar flow conditions. The water surface in the tank is maintained at constant level above the center of the orifice. If the fluid jet has a diameter of 1.6 cm at its vena contracta, then the coefficient of contraction is ______ (rounded off to two decimal places).
GATE→2026→Fluid Mechanics and Mechanical Operations→Fluid Mechanics and Mechanical Operations
Q6
MCQ[2 Marks]
Consider a flow with the following velocity field v⃗=(x+y)i^+(y+z)j^+(z+x)k^\vec{v} = (x+y)\hat{i} + (y+z)\hat{j} + (z+x)\hat{k} where i^\hat{i}, j^\hat{j} and k^\hat{k} are the unit vectors in the xx, yy and zz directions, respectively. Which one of the following is CORRECT?
GATE→2026→Fluid Mechanics and Mechanical Operations→Fluid Mechanics and Mechanical Operations
Q7
MCQ[2 Marks]
The gross energy requirement, to reduce a very large feed of coal to such a size that 80% of the product passes through a 100 μm100~\mu\text{m} screen, is 13 kWh per ton of feed. In a process, 250 tons h−1\text{h}^{-1} of coal is crushed. The range of feed sizes is such that 80% of the feed passes through an opening of 100 mm. The product size range is to be such that 80% of the product passes through an opening of 25 mm. According to the Bond's law, which one of the following is the power consumption (in kW)?
GATE→2026→Fluid Mechanics and Mechanical Operations→Fluid Mechanics and Mechanical Operations
Q8
MCQ[2 Marks]
Laboratory filtration is conducted at constant pressure drop of 200 kPa on a slurry of CaCO3\text{CaCO}_3 in water at room temperature. The time taken to collect filtrate is shown in the table. Filtrate volume collected (VV in m3^3) | Time (tt in s) 1×10−31 \times 10^{-3} | 40 2×10−32 \times 10^{-3} | 100 The filter area is 0.05 m20.05~\text{m}^2 and viscosity of filtrate is 10−310^{-3} Pa s. Which one of the following is the filter medium resistance (in m−1^{-1})?
GATE→2026→Fluid Mechanics and Mechanical Operations→Fluid Mechanics and Mechanical Operations
Q9
NAT[2 Marks]
When a cylindrical capillary glass tube, open at both ends, is vertically inserted in a pool of water, the water level in the tube rises to 7 cm relative to the water level outside the tube. Consider that the surface tension of water is 0.07 N m−10.07~\text{N m}^{-1} and that the contact angle of water on glass is 0∘0^\circ. The density of water is 1000 kg m−31000~\text{kg m}^{-3}, and the local acceleration due to gravity is 10 m s−210~\text{m s}^{-2}. The diameter of the capillary tube (in μm\mu\text{m}) is ______ (rounded off to the nearest integer).
GATE→2026→Fluid Mechanics and Mechanical Operations→Fluid Mechanics and Mechanical Operations
Q10
NAT[2 Marks]
Consider a two-dimensional, steady, laminar flow of an incompressible fluid with zero pressure gradient, over a thin horizontal flat plate of length 2 m. The free stream velocity is 1 m s−11~\text{m s}^{-1}. A boundary layer thickness of 1 mm is observed at a distance of 0.25 m from the leading edge of the plate. At 1 m from the leading edge, the boundary layer thickness (in mm) is ______ (rounded off to the nearest integer).
GATE→2026→Fluid Mechanics and Mechanical Operations→Fluid Mechanics and Mechanical Operations
Q11
NAT[2 Marks]
The velocity profile for a fully developed laminar flow of an incompressible Newtonian fluid, at steady state, through a horizontal infinitely wide and long slit of gap 0.01 m0.01~\text{m} is given by the following equation: u(y)=7.5−3×105y2u(y) = 7.5 - 3 \times 10^5 y^2 where yy is the vertical distance measured from the center of the slit. The average velocity of the fluid (in m s−1\text{m s}^{-1}) is ______ (rounded off to the nearest integer).
GATE→2025→Fluid Mechanics and Mechanical Operations→Fluid Mechanics and Mechanical Operations
Q12
MCQ[1 Mark]
The sum of the components of the force due to pressure and shear at the solid-fluid boundary of a solid body in the direction normal to the flow is
GATE→2025→Fluid Mechanics and Mechanical Operations→Fluid Mechanics and Mechanical Operations
Q13
MCQ[1 Mark]
Choose the CORRECT option for pathlines, streaklines and streamlines for a STEADY flow field.
GATE→2025→Fluid Mechanics and Mechanical Operations→Fluid Mechanics and Mechanical Operations
Q14
MCQ[2 Marks]
A catalyst particle is modeled as a symmetrical double cone solid as shown in the figure. The sphericity of the particle is given by
Figure for Question 14
GATE→2025→Fluid Mechanics and Mechanical Operations→Fluid Mechanics and Mechanical Operations
Q15
MSQ[2 Marks]
For a steady state, fully developed laminar flow of a Newtonian fluid through a cylindrical pipe at a constant volumetric flow rate, which of the following statements regarding pressure drop (ΔP\Delta P) is/are TRUE?
GATE→2025→Fluid Mechanics and Mechanical Operations→Fluid Mechanics and Mechanical Operations
Q16
NAT[2 Marks]
A leaf filter is operated at 1 atm (gauge)... The volumetric flow rate of the filtrate at 1 hour is ______ ×10−3 m3/s\times 10^{-3}\text{ m}^3\text{/s} (rounded off to 2 decimal places).
GATE→2024→Fluid Mechanics and Mechanical Operations→Fluid Mechanics and Mechanical Operations
Q17
MCQ[1 Mark]
An infinitely long cylindrical water filament of radius RR surrounded by air... Pin−PoutP_{in} - P_{out} is
GATE→2024→Fluid Mechanics and Mechanical Operations→Fluid Mechanics and Mechanical Operations
Q18
MCQ[1 Mark]
Velocity field in incompressible flow is given, with vy=0v_y=0 at y=0y=0. The correct expression for vyv_y is
GATE→2024→Fluid Mechanics and Mechanical Operations→Fluid Mechanics and Mechanical Operations
Q19
NAT[1 Mark]
Steady laminar flow through pipe of radius 5.05.0 cm. Wall shear stress is 0.1 N m−20.1 \text{ N m}^{-2}. Magnitude of shear stress at radial distance 1.01.0 cm from axis is.
GATE→2024→Fluid Mechanics and Mechanical Operations→Fluid Mechanics and Mechanical Operations
Q20
MCQ[2 Marks]
Consider steady, fully-developed, uni-directional laminar flow of an incompressible Newtonian fluid between two plates separated by 2H2H driven by pressure gradient and bottom plate motion. Which option represents the x-component of fluid velocity vector?
Figure for Question 20
GATE→2024→Fluid Mechanics and Mechanical Operations→Fluid Mechanics and Mechanical Operations
Q21
NAT[2 Marks]
Metallic spherical particle density 7001 kg m−37001 \text{ kg m}^{-3}, diameter 1 mm1 \text{ mm} settling in gas... drag coefficient CD=0.44C_D = 0.44. Terminal settling velocity in m s−1\text{m s}^{-1} is.
GATE→2024→Fluid Mechanics and Mechanical Operations→Fluid Mechanics and Mechanical Operations
Q22
NAT[2 Marks]
Water pumped from Reservoir 1 to Reservoir 2 at height 5050 m through pipe of 1010 cm diameter and 100100 m length. Darcy friction factor f=0.06f=0.06. Pump power in kW is.
Figure for Question 22
GATE→2024→Fluid Mechanics and Mechanical Operations→Fluid Mechanics and Mechanical Operations
Q23
NAT[2 Marks]
Venturi meter throat d=2d=2 cm, pipe D=6D=6 cm. If volumetric flow rate is doubled Q2=2Q1Q_2 = 2 Q_1, ratio of manometer readings Δh2/Δh1\Delta h_2 / \Delta h_1 is.
Figure for Question 23
GATE→2023→Fluid Mechanics and Mechanical Operations→Fluid Mechanics and Mechanical Operations
Q24
MCQ[1 Mark]
For packed-bed with Kozeny-Carman equation (Rep<1Re_p < 1), minimum fluidization velocity is proportional to DpnD_p^n. What is exponent nn?
GATE→2023→Fluid Mechanics and Mechanical Operations→Fluid Mechanics and Mechanical Operations
Q25
MSQ[1 Mark]
For fully developed turbulent pipe flow, which statements are CORRECT?
GATE→2023→Fluid Mechanics and Mechanical Operations→Fluid Mechanics and Mechanical Operations
Q26
NAT[1 Mark]
Capillary tube viscometer parameters given. Viscosity k×10−3 Pa sk \times 10^{-3} \text{ Pa s}, value of kk is.
GATE→2023→Fluid Mechanics and Mechanical Operations→Fluid Mechanics and Mechanical Operations
Q27
NAT[2 Marks]
Pump operating between suction and discharge conditions at 80%80\% efficiency. Power required (in kW) is.
GATE→2023→Fluid Mechanics and Mechanical Operations→Fluid Mechanics and Mechanical Operations
Q28
NAT[2 Marks]
Cylindrical tank draining through nozzle. Absolute value of dhdt\frac{dh}{dt} when h=51h=51 cm is mm s−1^{-1}.
Figure for Question 28
GATE→2023→Fluid Mechanics and Mechanical Operations→Fluid Mechanics and Mechanical Operations
Q29
NAT[2 Marks]
Solid spherical particle (100100 um diameter) rising/settling in water column under Stokes law. Absolute value of vtv_t (in mm s−1^{-1}) is.
GATE→2022→Fluid Mechanics and Mechanical Operations→Fluid Mechanics and Mechanical Operations
Q30
MCQ[1 Mark]
Consider turbulent pipe flow. On moving away from wall towards center, rz-component of Reynolds stress
GATE→2022→Fluid Mechanics and Mechanical Operations→Fluid Mechanics and Mechanical Operations
Q31
MCQ[2 Marks]
Water jet of diameter 22 cm striking vertical plate with hole diameter 11 cm at 20 m s−120 \text{ m s}^{-1}. Horizontal force required to hold plate stationary is N.
Figure for Question 31
GATE→2022→Fluid Mechanics and Mechanical Operations→Fluid Mechanics and Mechanical Operations
Q32
MCQ[2 Marks]
Rod pulled coaxially inside pipe with annular Newtonian fluid. Magnitude of pulling force per unit rod length is
Figure for Question 32
GATE→2022→Fluid Mechanics and Mechanical Operations→Fluid Mechanics and Mechanical Operations
Q33
NAT[2 Marks]
Pump transferring liquid between reservoirs through pipe with friction factor 0.010.01. Required power of the pump is kW.
Figure for Question 33
GATE→2022→Fluid Mechanics and Mechanical Operations→Fluid Mechanics and Mechanical Operations
Q34
NAT[2 Marks]
Venturi meter with specified dimensions and pressure drop 5050 kPa. Estimated flow rate of water is ×10−3 m3s−1\times 10^{-3} \text{ m}^3 \text{s}^{-1}.
GATE→2022→Fluid Mechanics and Mechanical Operations→Fluid Mechanics and Mechanical Operations
Q35
NAT[2 Marks]
Constant-rate cake filtration with filtrate volumes and pressure drop. Pressure drop across cake at 2 min is kPa.