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Momentum Transfer

11 Questions
GATE→2026→Transport Phenomena and Rate Processes→Momentum Transfer
Q1
NAT[1 Mark]
Two parallel plates, with Newtonian incompressible liquid in between, are 2 mm apart. The upper plate is stationary and the lower plate moves with a velocity of 4 m/s4\text{ m/s}. A force per unit area of 5 N/m25\text{ N/m}^2 is applied parallel to the lower plate to maintain its motion. The viscosity of the liquid (rounded off to two decimal places) is ___ ×10−3 N⋅s/m2\times 10^{-3}\text{ N}\cdot\text{s/m}^2.
GATE→2026→Transport Phenomena and Rate Processes→Momentum Transfer
Q2
MCQ[2 Marks]
The equation below represents steady-state laminar flow of a fluid through a horizontal tube: η1rddr(rdvzdr)−dPdz=0\eta \frac{1}{r} \frac{d}{dr}\left(r \frac{dv_z}{dr}\right) - \frac{dP}{dz} = 0\nWhich one of the following statements related to the above case is NOT correct? (A) The fluid is Newtonian (B) Shear stress is maximum at the center (r=0r=0) (C) Radial velocity is zero (D) There is no variation of vzv_z in zz-direction
GATE→2026→Transport Phenomena and Rate Processes→Momentum Transfer
Q3
MSQ[2 Marks]
Choose the correct option(s). Permeability of a porous bed made of spherical particles is/are: (A) Independent of particle size (B) Increases with increase in particle size (C) Decreases with increase in particle size (D) Affected by particle size distribution
GATE→2025→Transport Phenomena and Rate Processes→Momentum Transfer
Q4
MCQ[1 Mark]
At high temperatures, which one of the following empirical expressions correctly describes the variation of dynamic viscosity μ\mu of a Newtonian liquid with absolute temperature TT? Given: AA and BB are positive constants. (A) μ=A+BT\mu = A + BT (B) μ=Aexp⁡(−BT)\mu = A \exp\left(-\frac{B}{T}\right) (C) μ=Aexp⁡(BT)\mu = A \exp(BT) (D) μ=Aexp⁡(BT)\mu = A \exp\left(\frac{B}{T}\right)
GATE→2025→Transport Phenomena and Rate Processes→Momentum Transfer
Q5
MSQ[1 Mark]
Consider a fully developed, steady, one-dimensional, laminar flow of a Newtonian liquid through a pipe. The maximum velocity in the pipe is proportional to which of the following quantities?\nGiven: ΔP\Delta P is the pressure drop, μ\mu is dynamic viscosity, and RR and LL are radius and length of the pipe, respectively. (A) ΔP\Delta P (B) 1/R21/R^2 (C) 1/μ1/\mu (D) 1/L1/L
GATE→2023→Transport Phenomena and Rate Processes→Momentum Transfer
Q6
MCQ[1 Mark]
For laminar fluid flow through a smooth circular tube, the relation between friction factor (ff) and Reynolds number (ReRe) is (A) f=16Ref = \frac{16}{Re} (B) f=24Ref = \frac{24}{Re} (C) f=16Ref = \frac{16}{\sqrt{Re}} (D) f=24Ref = \frac{24}{\sqrt{Re}}
GATE→2023→Transport Phenomena and Rate Processes→Momentum Transfer
Q7
NAT[1 Mark]
A liquid of density 900 kg m−3900\text{ kg m}^{-3} is flowing over a flat plate with a free stream velocity of 0.1 m s−10.1\text{ m s}^{-1}. The laminar boundary layer thickness at a distance of 0.2 m0.2\text{ m} from the leading edge of the plate is 0.007 m0.007\text{ m}. The viscosity of the liquid in centipoise is ___ (round off to 2 decimal places). (Given: 1 centipoise=10−3 kg m−1s−11\text{ centipoise} = 10^{-3}\text{ kg m}^{-1}\text{s}^{-1})
GATE→2023→Transport Phenomena and Rate Processes→Momentum Transfer
Q8
NAT[2 Marks]
A chimney as shown in the figure requires to have natural draft (pressure difference between the furnace and the bottom of chimney, P0−P1P_{0}-P_{1}) of 1.0133×103 Pa1.0133\times 10^{3}\text{ Pa}. If the density difference between the air and flue is 0.5 kg m−30.5\text{ kg m}^{-3}, the minimum height (hh) of the chimney in meters is ___ (round off to nearest integer). (Given: acceleration due to gravity, g=9.81 m s−2g = 9.81\text{ m s}^{-2})
Figure for Question 8
GATE→2022→Transport Phenomena and Rate Processes→Momentum Transfer
Q9
NAT[1 Mark]
A Newtonian incompressible liquid is contained between two parallel metal plates separated by 10−3 m10^{-3}\text{ m}. A stress of 5 Pa5\text{ Pa} is required to maintain the upper plate in motion with a constant speed of 2 m s−12\text{ m s}^{-1} in the horizontal direction relative to the bottom plate. The viscosity of liquid contained between the plates is ___ ×10−3 Pa-s\times 10^{-3}\text{ Pa-s} (answer rounded off to 1 decimal place).
Figure for Question 9
GATE→2022→Transport Phenomena and Rate Processes→Momentum Transfer
Q10
MSQ[2 Marks]
A non-rotating smooth solid spherical object is fixed in the stream of an inviscid incompressible fluid of density ρ\rho. The flow is horizontal, slow, steady, and fully developed far from the object as shown by the streamline arrows near point O. Which of the following statement(s) is (are) TRUE? (A) The velocity of the fluid at the point A is zero (B) The fluid pressure at the point A exceeds that at point O by the amount ρv22\frac{\rho v^2}{2}, where vv is the fluid velocity at point O (C) Fluid moving precisely along OA will turn perpendicular to OA to circumvent the object (D) On each side of the central streamline OA, the flow will be deflected round the object
Figure for Question 10
GATE→2022→Transport Phenomena and Rate Processes→Momentum Transfer
Q11
NAT[2 Marks]
A spherical gas bubble of radius 0.01 mm0.01\text{ mm} is entrapped in molten steel held at 1773 K1773\text{ K}. If the pressure outside the bubble is 1.5 bar1.5\text{ bar}, the pressure inside the bubble is ___ bar\text{bar} (round off to 1 decimal place).\nGiven: 1 bar=105 Pa1\text{ bar} = 10^5\text{ Pa} and the surface tension of the steel at 1773 K1773\text{ K} is 1.4 N m−11.4\text{ N m}^{-1}.

Heat Transfer

11 Questions
GATE→2026→Transport Phenomena and Rate Processes→Heat Transfer
Q12
MCQ[1 Mark]
Which one of the following options is correct? For a solid immersed in a fluid, the convective heat transfer coefficient across the solid-fluid interface is NOT dependent on: (A) Solid-fluid interfacial area (B) Thermal conductivity of solid (C) Roughness of solid surface (D) Viscosity of fluid
GATE→2026→Transport Phenomena and Rate Processes→Heat Transfer
Q13
NAT[2 Marks]
For a cylindrical furnace with 0.1 m0.1\text{ m} diameter and 0.2 m0.2\text{ m} height operating at 1873 K1873\text{ K}, power needed is ___ W.
Figure for Question 13
GATE→2025→Transport Phenomena and Rate Processes→Heat Transfer
Q14
MCQ[2 Marks]
Radiative heat flux q˙\dot{q} at a hot surface at a temperature TsT_s can be expressed as q˙=A⋅f(Ts,T∞)(Ts−T∞)\dot{q} = A \cdot f(T_s, T_\infty)(T_s - T_\infty) where AA is a constant and T∞T_\infty is the temperature of the surroundings. The function f(Ts,T∞)f(T_s, T_\infty) is given by (A) (Ts+T∞)2(Ts−T∞)(T_s + T_\infty)^2(T_s - T_\infty) (B) (Ts2+T∞2)(Ts+T∞)(T_s^2 + T_\infty^2)(T_s + T_\infty) (C) (Ts2−T∞2)(Ts+T∞)(T_s^2 - T_\infty^2)(T_s + T_\infty) (D) (Ts−T∞)2(Ts+T∞)(T_s - T_\infty)^2(T_s + T_\infty)
GATE→2025→Transport Phenomena and Rate Processes→Heat Transfer
Q15
NAT[2 Marks]
Temperatures at two sides of a 0.4 m0.4\text{ m} thick copper plate are 1000∘C1000^{\circ}\text{C} and 500∘C500^{\circ}\text{C}. Assuming steady state, one-dimensional conductive heat transfer through the wall and ignoring end-effects, the magnitude of the heat flux through the wall is ___ ×105 W m−2\times 10^5\text{ W m}^{-2} (in integer). (Given: Thermal conductivity of copper is 400 W m−1K−1400\text{ W m}^{-1}\text{K}^{-1})
GATE→2024→Transport Phenomena and Rate Processes→Heat Transfer
Q16
MCQ[1 Mark]
As shown in the figure, two rods of different metals of equal lengths L/2L/2, diameter dd, and constant thermal conductivities k1k_1 and k2k_2 (with k1>k2k_1 > k_2) are connected perfectly. Which one of the graphs represents the steady-state temperature distribution?
Figure for Question 16
GATE→2024→Transport Phenomena and Rate Processes→Heat Transfer
Q17
MCQ[2 Marks]
As shown in the figure, the right end of a slender, long solid cylindrical metal rod of thermal conductivity kk, length LL and diameter dd is in contact with an infinite liquid heat sink at T0T_0. At steady-state, temperatures are T2T_2 at the right end and T0T_0 at the heat sink, with convection coefficient hh. The temperature of the left end T1T_1 at steady-state is determined by fin/rod heat transfer balances.
Figure for Question 17
GATE→2024→Transport Phenomena and Rate Processes→Heat Transfer
Q18
NAT[2 Marks]
A long metallic cylindrical rod of radius rr, length LL and electrical resistivity ρe\rho_e is kept in vacuum and is carrying an electric current of II. The only way it loses heat to the ambient is via radiation. If the ambient temperature is T0T_0, then the steady-state temperature of the rod is ___ K\text{K} (Round off to the nearest integer).\nGiven: Stefan-Boltzmann constant =5.667×10−8 W m−2K−4= 5.667 \times 10^{-8}\text{ W m}^{-2}\text{K}^{-4}, r=0.1 mm=10−4 mr = 0.1\text{ mm} = 10^{-4}\text{ m}, I=0.3 AI = 0.3\text{ A}, L=1 mL = 1\text{ m}, ρe=10−8 Ωm\rho_e = 10^{-8}\text{ }\Omega\text{m}, T0=300 KT_0 = 300\text{ K}.
GATE→2023→Transport Phenomena and Rate Processes→Heat Transfer
Q19
NAT[2 Marks]
Two circular surfaces A and B with the values of emissivity ε\varepsilon, temperature TT, and respective view factors are shown in the figure. Surface A: radius 1 m1\text{ m} (area A1=π m2A_1 = \pi\text{ m}^2), ε1=0.7\varepsilon_1 = 0.7, T1=800 KT_1 = 800\text{ K}, FAB=0.172F_{AB} = 0.172. Surface B: radius 1 m1\text{ m} (area A2=π m2A_2 = \pi\text{ m}^2), ε2=0.8\varepsilon_2 = 0.8, T2=500 KT_2 = 500\text{ K}, FBA=0.172F_{BA} = 0.172. Net heat flow rate by radiation from surface A in kW is ___ (round off to 1 decimal place). Given: Stefan-Boltzmann constant σ=5.67×10−8 W m−2K−4\sigma = 5.67 \times 10^{-8}\text{ W m}^{-2}\text{K}^{-4}
Figure for Question 19
GATE→2022→Transport Phenomena and Rate Processes→Heat Transfer
Q20
MSQ[2 Marks]
Which of the following statement(s) is (are) TRUE about black body radiation? (A) Among all radiation emitted by an ideal black body at room temperature, the most intense radiation falls in the visible light spectrum (B) The total emissive power of an ideal black body is proportional to the square of its absolute temperature (C) The emissive power of an ideal black body peaks at a wavelength λ\lambda which is inversely proportional to its absolute temperature (D) The radiant energy emitted by an ideal black body is greater than that emitted by the non-black body at all temperatures above 0 K0\text{ K}
GATE→2022→Transport Phenomena and Rate Processes→Heat Transfer
Q21
NAT[2 Marks]
A rectangular block made of Material I and Material II of identical cross sections has a temperature (TT) of 435 K435\text{ K} and 400 K400\text{ K} at the bottom and top surfaces, respectively. Assuming purely steady state conductive heat transfer, the temperature at the interface is ___ K\text{K} (round off to nearest integer). (Given: The two parts of the block made of Material I and Material II have equal thickness of 25 mm25\text{ mm} each. The thermal conductivities of Material I and Material II are 50 W⋅m−1⋅K−150\text{ W}\cdot\text{m}^{-1}\cdot\text{K}^{-1} and 200 W⋅m−1⋅K−1200\text{ W}\cdot\text{m}^{-1}\cdot\text{K}^{-1} respectively.)
Figure for Question 21
GATE→2022→Transport Phenomena and Rate Processes→Heat Transfer
Q22
NAT[2 Marks]
Air at 300 K300\text{ K} is passed at a mass flow rate of 1.5 kg⋅s−11.5\text{ kg}\cdot\text{s}^{-1} through a metallic tube of inner diameter 0.08 m0.08\text{ m}. Inner wall temperature of the tube is maintained at 700 K700\text{ K}. Temperature of the air leaving the tube is 600 K600\text{ K}. Assuming that heat transfer occurs entirely by steady state convection, length of the tube is ___ m\text{m} (round off to 2 decimal places).\nGiven: convective heat transfer coefficient h=500 W⋅m−2⋅K−1h = 500\text{ W}\cdot\text{m}^{-2}\cdot\text{K}^{-1}, specific heat Cp=1080 J⋅kg−1⋅K−1C_p = 1080\text{ J}\cdot\text{kg}^{-1}\cdot\text{K}^{-1}, π=3.14\pi = 3.14.

Mass Transfer and Dimensional Analysis

3 Questions
GATE→2026→Transport Phenomena and Rate Processes→Mass Transfer and Dimensional Analysis
Q23
MCQ[1 Mark]
Which one of the following options is correct? In convective heat transfer for laminar flow over a flat plate, Nusselt number is a function of Reynolds and Prandtl numbers. Similarly, in convective mass transfer, Sherwood number is a function of: (A) Schmidt number and Reynolds number (B) Weber number and Reynolds number (C) Schmidt number and Weber number (D) Weber number and Prandtl number
GATE→2024→Transport Phenomena and Rate Processes→Mass Transfer and Dimensional Analysis
Q24
MCQ[1 Mark]
Match the laws listed in Column I with the corresponding material properties listed in Column II:\nColumn I:\nP. Hooke's law\nQ. Fick's law\nR. Fourier's law\nS. Darcy's law\nColumn II: 1. Thermal conductivity 2. Young's modulus 3. Permeability 4. Diffusivity (A) P-2, Q-1, R-4, S-3 (B) P-4, Q-3, R-1, S-2 (C) P-2, Q-4, R-1, S-3 (D) P-4, Q-3, R-2, S-1
GATE→2023→Transport Phenomena and Rate Processes→Mass Transfer and Dimensional Analysis
Q25
MCQ[2 Marks]
Match the transport processes in Column I with the relationships in Column II.\nColumn I: (P) Molecular momentum transport (Q) Molecular mass transport (R) Molecular energy transport (S) Radiation energy transport\nColumn II: (1) Stefan-Boltzmann law (2) Newton's law of viscosity (3) Fick's law (4) Fourier law (A) P-2, Q-3, R-4, S-1 (B) P-4, Q-3, R-2, S-1 (C) P-3, Q-1, R-4, S-2 (D) P-2, Q-1, R-4, S-3

Dimensional Analysis

5 Questions
GATE→2025→Transport Phenomena and Rate Processes→Dimensional Analysis
Q26
NAT[1 Mark]
For an application where the Reynolds number is to be kept constant, a liquid with a density of 1 g cm−31\text{ g cm}^{-3} and viscosity 0.01 Poise0.01\text{ Poise} results in a characteristic speed of 1 cm s−11\text{ cm s}^{-1}. If this liquid is replaced by another with a density of 1.25 g cm−31.25\text{ g cm}^{-3} and viscosity of 0.015 Poise0.015\text{ Poise}, the characteristic velocity will be ___ cm s−1\text{cm s}^{-1} (rounded off to one decimal place).
GATE→2025→Transport Phenomena and Rate Processes→Dimensional Analysis
Q27
NAT[2 Marks]
The reaction represented by A→BA \rightarrow B follows first order kinetics. At a given temperature, 20%20\% of the reaction is completed in 223 s223\text{ s}. The time taken to complete 50%50\% of the reaction at the same temperature is ___ s\text{s} (rounded off to the nearest integer).
GATE→2024→Transport Phenomena and Rate Processes→Dimensional Analysis
Q28
MCQ[2 Marks]
Match the dimensionless numbers listed in Column I with their applications to transport phenomena listed in Column II.\nColumn I:\nP. Reynolds number\nQ. Schmidt number\nR. Prandtl number\nS. Biot number\nColumn II: 1. Momentum and mass transfer 2. Momentum and heat transfer 3. Convective and conductive heat transfer 4. Laminar to turbulent flow (A) P-4, Q-1, R-3, S-2 (B) P-3, Q-2, R-4, S-1 (C) P-4, Q-1, R-2, S-3 (D) P-2, Q-3, R-1, S-4
GATE→2023→Transport Phenomena and Rate Processes→Dimensional Analysis
Q29
NAT[1 Mark]
The rate constant of a reaction at 400 K400\text{ K} is three times the value at 300 K300\text{ K}. The activation energy of the reaction in kJ mol−1\text{kJ mol}^{-1} is ___ (round off to 1 decimal place). Given: Universal gas constant, R=8.314 J mol−1K−1R = 8.314\text{ J mol}^{-1}\text{K}^{-1}
GATE→2022→Transport Phenomena and Rate Processes→Dimensional Analysis
Q30
MCQ[1 Mark]
In fluid flow, the dimensionless number that describes the transition from laminar to turbulent flow is (A) Reynolds number (B) Schmidt number (C) Biot number (D) Prandtl number