Question 1
Marks: 1
The village was nestled in a green spot, _______ the ocean and the hills.
- A. through
- B. in
- C. at
- D. between
Answer: D. between
Attempt the GATE XE (Engineering Sciences) 2023 previous year paper in real CBT exam mode or practice mode with the official answer key. Step-by-step explanations are coming soon.
All GATE XE (Engineering Sciences) papers
87 questions. Answers are shown only where the official answer key is available.
Marks: 1
The village was nestled in a green spot, _______ the ocean and the hills.
Answer: D. between
Marks: 1
Disagree : Protest : : Agree : _______ (By word meaning)
Answer: C. Recommend
Marks: 1
A βfrabjousβ number is defined as a 3 digit number with all digits odd, and no two adjacent digits being the same. For example, 137 is a frabjous number, while 133 is not. How many such frabjous numbers exist?
Answer: D. 80
Marks: 1
Which one among the following statements must be TRUE about the mean and the median of the scores of all candidates appearing for GATE 2023?
Answer: C. At most half the candidates have a score that is larger than the median.
Marks: 1
In the given diagram, ovals are marked at different heights (h) of a hill. Which one of the following options P, Q, R, and S depicts the top view of the hill?

Answer: B. Q
Marks: 2
Residency is a famous housing complex with many well-established individuals among its residents. A recent survey conducted among the residents of the complex revealed that all of those residents who are well established in their respective fields happen to be academicians. The survey also revealed that most of these academicians are authors of some best-selling books. Based only on the information provided above, which one of the following statements can be logically inferred with certainty?
Marks: 2
Ankita has to climb 5 stairs starting at the ground, while respecting the following rules: 1. At any stage, Ankita can move either one or two stairs up. 2. At any stage, Ankita cannot move to a lower step. Let πΉ(π) denote the number of possible ways in which Ankita can reach the ππ‘β stair. For example, πΉ(1) = 1, πΉ(2) = 2, πΉ(3) = 3. The value of πΉ(5) is _______.
Answer: A. 8
Marks: 2
The information contained in DNA is used to synthesize proteins that are necessary for the functioning of life. DNA is composed of four nucleotides: Adenine (A), Thymine (T), Cytosine (C), and Guanine (G). The information contained in DNA can then be thought of as a sequence of these four nucleotides: A, T, C, and G. DNA has coding and non-coding regions. Coding regionsβwhere the sequence of these nucleotides are read in groups of three to produce individual amino acidsβconstitute only about 2% of human DNA. For example, the triplet of nucleotides CCG codes for the amino acid glycine, while the triplet GGA codes for the amino acid proline. Multiple amino acids are then assembled to form a protein. Based only on the information provided above, which of the following statements can be logically inferred with certainty? (i) The majority of human DNA has no role in the synthesis of proteins. (ii) The function of about 98% of human DNA is not understood.
Answer: D. neither (i) nor (ii)
Marks: 2
Which one of the given figures P, Q, R and S represents the graph of the following function? π(π₯) = | |π₯+ 2| β|π₯β1| |

Answer: A. P
Marks: 2
An opaque cylinder (shown below) is suspended in the path of a parallel beam of light, such that its shadow is cast on a screen oriented perpendicular to the direction of the light beam. The cylinder can be reoriented in any direction within the light beam. Under these conditions, which one of the shadows P, Q, R, and S is NOT possible?

Answer: D. S
Marks: 1
Let π΄ be a 3 Γ 3 real matrix having eigenvalues 1, 2, and 3. If π΅= π΄2 + 2π΄+ πΌ, where πΌ is the 3 Γ 3 identity matrix, then the eigenvalues of π΅ are
Answer: A. 4, 9, 16
Marks: 1
Let π: β2 ββ be a function defined by π(π₯, π¦) = { π₯π¦ |π₯| + π¦ , π¦β β|π₯| 0 , otherwise. Then which one of the following statement is TRUE?
Answer: A. π is NOT continuous at (0,0).
Marks: 1
If the quadrature formula β«π(π₯)ππ₯ 1 β1 β1 9 (π1π(β1) + π2π(1 2) + π3π(1)) is exact for all polynomials of degree less than or equal to 2, then
Answer: A. π1 + π2 4 + π3 = 6
Marks: 1
The second smallest eigenvalue of the eigenvalue problem π2π¦ ππ₯2 + (πβ3)π¦= 0, π¦(0) = π¦(π) = 0, is
Answer: C. 7
Marks: 1
Which one of the following functions is differentiable at π§= 0 but NOT differentiable at any other point in the complex plane β?
Answer: A. π(π§) = π§|π§|, π§ββ
Type: NAT | Marks: 1
If the polynomial π(π₯) = π0 + π1π₯+ π2π₯(π₯β1) + π3π₯(π₯β1)(π₯β2) interpolates the points (0, 2), (1, 3), (2, 2), and (3, 5), then the value of π( 5 2) is _________ (round off to 2 decimal places).
Answer: 2.60 to 2.65
Type: NAT | Marks: 1
The value of π for which the vector field πΉβ(π₯, π¦) = (4π₯ππ¦2 β2 π₯ π¦π)πΜ + (2π₯4π¦β3π₯2π¦2)πΜ is a conservative vector field, is _________________ (in integer).
Answer: 3
Marks: 2
Let π= [ 4 β2 2 6 β3 4 3 β2 3 ], and π= [ 3 β2 2 4 β4 6 2 β3 5 ] . The eigenvalues of both π and π are 1, 1, and 2. Which one of the following statements is TRUE?
Answer: B. π is diagonalizable but π is NOT diagonalizable
Marks: 2
The surface area of the portion of the paraboloid π§= π₯2 + π¦2 that lies between the planes π§= 0 and π§= 1 4 is
Answer: A. π 6 (2β2 β1)
Type: NAT | Marks: 2
The probability of a person telling the truth is 4 6 . An unbiased die is thrown by the same person twice and the person reports that the numbers appeared in both the throws are same. Then the probability that actually the numbers appeared in both the throws are same is __________ (round off to 2 decimal places).
Answer: 0.26 to 0.30
Type: NAT | Marks: 2
Let π’(π₯, π‘) be the solution of the initial boundary value problem ππ’ ππ‘β π2π’ ππ₯2 = 0, π₯β(0, 2), π‘> 0 π’(π₯, 0) = sin(ππ₯), π₯β(0, 2) π’(0, π‘) = π’(2, π‘) = 0. Then the value of ππ2 (π’( 1 2 , 1) βπ’( 3 2 , 1)) is __________ (in integer).
Answer: 2
Marks: 1
Match the following measuring instruments with the appropriate figures. I β Pitot probe II β Pitot-static probe III β Piezometer

Answer: B. I β R; II β Q; III β P
Marks: 1
Among the following non-dimensional numbers, which one characterizes periodicity present in a transient flow?
Answer: B. Strouhal number
Marks: 1
For an incompressible boundary layer flow over a flat plate shown in the figure, the momentum thickness is expressed as

Answer: C. β« π’ πβ (1 βπ’ πβ ) ππ¦ β 0
Marks: 1
Among the shear stress versus shear strain rate curves shown in the figure, which one corresponds to a shear thinning fluid?

Answer: C. R
Marks: 1
Consider steady incompressible flow over a flat plate, where the dashed line represents the edge of the boundary layer, as shown in the figure. Which one among the following statements is true?

Answer: D. Bernoulliβs equation cannot be applied in Region I.
Marks: 1
An inviscid steady incompressible flow is formed by combining a uniform flow with velocity πβ and a clockwise vortex of strength πΎ at the origin, as shown in the figure. Velocity potential (π) for the combined flow in polar coordinate (π, π) is

Answer: A. π= πΎπ 2 πβπβπ cos π
Marks: 1
Which of the following statements are true? (i) Conservation of mass for an unsteady incompressible flow can be represented as ββ πββ= 0, where πββ denotes velocity vector. (ii) Circulation is defined as the line integral of vorticity about a closed curve. (iii) For some fluids, shear stress can be a nonlinear function of the shear strain rate. (iv) Integration of the Bernoulliβs equation along a streamline under steady-state leads to the Eulerβs equation.
Answer: C. (i) and (iii) only
Marks: 1
For a two-dimensional flow field given as πββ= βπ₯πΜ + π¦πΜ, a streamline passes through points (2, 1) and (5, p). The value of p is
Answer: C. 2/5
Type: MSQ | Marks: 1
A stationary object is fully submerged in a static fluid, as shown in the figure. Here, CG and CB stand for center of gravity and center of buoyancy, respectively. Which one(s) among the following statements is/are true?

Answer: A. The object is in stable equilibrium if π¦πΆπΊ> π¦πΆπ΅.; C. The object is in neutral equilibrium if π¦πΆπΊ= π¦πΆπ΅.
Marks: 2
Consider steady fully-developed incompressible flow of a Newtonian fluid between two infinite parallel flat plates. The plates move in the opposite directions, as shown in the figure. In the absence of body force and pressure gradient, the ratio of shear stress at the top surface (π¦= π») to that at the bottom surface (π¦= 0) is

Answer: A. 1
Marks: 2
A two-dimensional incompressible flow field is defined as, πββ(π₯, π¦) = (π΄π₯π¦) πΜ + (π΅π¦2) πΜ where, π΄ and π΅ are constants. The dynamic viscosity of the Newtonian fluid is π. In the absence of body force, which among the following expressions represents the pressure gradient at the location (5, 0) in the concerned flow field?
Answer: C. ππ΄(βπΜ)
Marks: 2
For a potential flow, the fluid velocity is given by πββ(π₯, π¦) = π’πΜ + π£πΜ . The slope of the potential line at (π₯, π¦) is
Answer: C. βπ’ π£
Marks: 2
Consider steady incompressible flow of a Newtonian fluid over a horizontal flat plate, as shown in the figure. The boundary layer thickness is proportional to

Answer: B. π₯1/2
Type: MSQ | Marks: 2
In a steady two-dimensional compressible flow, π’ and π£ are the π₯- and π¦- components of flow velocity, respectively and π is the fluid density. Among the following pairs of relations, which one(s) perfectly satisfies/satisfy the definition of stream function, π, for this flow?
Answer: C. ππ’= ππ ππ¦ and ππ£= β ππ ππ₯; D. ππ’= β ππ ππ¦ and ππ£= ππ ππ₯
Type: NAT | Marks: 2
A water jet (density = 1000 kg/m3) is approaching a vertical plate, having an orifice at the center, as shown in the figure. While a part of the jet passes through the orifice, remainder flows along the plate. Neglect friction and assume both the inlet and exit jets to have circular cross-sections. If V = 5 m/s, π· = 100 mm and π = 25 mm, magnitude of the horizontal force (in N, rounded off to one decimal place) required to hold the plate in its position is ___________.

Answer: 183.0 to 185.0
Type: NAT | Marks: 2
Water (density = 1000 kg/m3) and alcohol (specific gravity = 0.7) enter a Y-shaped channel at flow rates of 0.2 m3/s and 0.3 m3/s, respectively. Their mixture leaves through the other end of the channel, as shown in the figure. The average density (in kg/m3) of the mixture is _______.

Answer: 820
Type: NAT | Marks: 2
The velocity and acceleration of a fluid particle are given as πββ= (βπΜ + 2πΜ) m/s and πβ= (β2πΜ β4πΜ) m/s2, respectively. The magnitude of the component of acceleration (in m/s2, rounded off to two decimal places) of the fluid particle along the streamline is _______.
Answer: 2.60 to 2.75
Type: NAT | Marks: 2
A hydraulic turbine with rotor diameter of 100 mm produces 200 W of power while rotating at 300 rpm. Another dynamically-similar turbine rotates at a speed of 1500 rpm. Consider both turbines to operate with the same fluid (identical density and viscosity), and neglect any gravitational effect. Then the power (in W, rounded off to nearest integer) produced by the second turbine is _______________.
Answer: 430 to 460
Type: NAT | Marks: 2
Water (density = 1000 kg/m3) flows steadily with a flow rate of 0.05 m3/s through a venturimeter having throat diameter of 100 mm. If the pipe diameter is 200 mm and losses are negligible, the pressure drop (in kPa, rounded off to one decimal place) between an upstream location in the pipe and the throat (both at the same elevation) is _______.
Answer: 18.5 to 19.5
Type: NAT | Marks: 2
Water flows around a thin flat plate (0.25 m long, 2 m wide) with a free stream velocity (πβ) of 1 m/s, as shown in the figure. Consider linear velocity profile ( π’ πβ= π¦ πΏ) for which the laminar boundary layer thickness is expressed as πΏ= 3.5π₯ βπ ππ₯ . For water, density = 1000 kg/m3 and dynamic viscosity = 0.001 kg/m.s. Net drag force (in N, rounded off to two decimal places) acting on the plate, neglecting the end effects, is ________.

Answer: 1.10 to 1.20
Type: NAT | Marks: 2
Axial velocity profile π’(π) for an axisymmetric flow through a circular tube of radius π is given as, π’(π) π = (1 βπ π ) 1 π β where π is the centerline velocity. If π refers to the area-averaged velocity (volume flow rate per unit area), then the ratio π/π for π= 1 (rounded off to two decimal places) is ______________.
Answer: 0.32 to 0.34
Type: NAT | Marks: 2
A stationary circular pipe of radius π = 0.5 m is half filled with water (density = 1000 kg/m3), whereas the upper half is filled with air at atmospheric pressure, as shown in the figure. Acceleration due to gravity is π= 9.81 m/s2. The magnitude of the force per unit length (in kN/m, rounded off to one decimal place) applied by water on the pipe section AB is _______. Material Science (XE-C)

Answer: 2.2 to 2.4
Marks: 1
A plane truss is simply supported at P and R as shown. A downward force F is applied at hinge Q. The axial force developed in member PS is

Answer: B. β5 2 πΉ Compressive
Marks: 1
A massless rigid rod OP of length L is hinged frictionlessly at O. A concentrated mass m is attached to end P of the rod. Initially, the rod OP is horizontal. Then, it is released from rest. There is gravity as shown. The rod acquires an angular velocity as it swings. The clockwise angular velocity of the rod, when it first reaches the vertical position as shown, is

Answer: B. β 2 π πΏ
Marks: 1
Two equivalent descriptions of the state of stress at a point are shown in the figure. The normal stresses π1 and π2 as shown on the right must be, respectively,

Answer: A. πo and βπo
Marks: 1
The state of strain at a point in a machine component is given as ππ₯π₯= 2.5 Γ 10β4, ππ¦π¦= 2.0 Γ 10β4, ππ§π§= β1.5 Γ 10β4, ππ₯π¦= 2.5 Γ 10β4, ππ¦π§= β0.5 Γ 10β4, ππ§π₯= β1.0 Γ 10β4. The volumetric strain at this point is
Answer: B. 3 Γ 10β4
Marks: 1
A thin walled, closed cylindrical vessel of inside diameter π and wall thickness π‘ contains a fluid under pressure π. The figure below shows a part of the cylindrical vessel; end caps are not shown. Consider the small element shown with sides parallel and perpendicular to the axis of the cylinder. The stresses π1 and π2 are

Answer: A. π1 = ππ 2π‘; π2 = ππ 4π‘
Type: MSQ | Marks: 1
A spring mass system is shown in the figure below. Take the acceleration due to gravity as π = 9.81 m/s2. The static deflection due to weight and the time period of oscillations, respectively, are

Answer: A. 0.392 m and 1.26 s
Type: NAT | Marks: 1
A rod is subjected to three forces as shown in the figure on the left. An equivalent force system with forces F1, F2 and moment M is shown in the figure on the right. The value of M (in N-m) is______(rounded off to one decimal place).

Answer: 117.0 to 118.0
Type: NAT | Marks: 1
A simply supported beam of length 3 m is loaded as shown in the figure. The magnitude of the shear force (in kN) at the mid-point of the beam is______(rounded off to one decimal place).

Answer: 4.9 to 5.1
Type: NAT | Marks: 1
For a plane stress problem, the principal stresses are 100 MPa and 50 MPa. The magnitude of maximum shear stress (in MPa) in the material is______(rounded off to one decimal place).
Answer: 49.5 to 50.5
Marks: 2
A solid uniform rigid disk of mass π and radius π rolls without slipping along a horizontal surface PQ. The speed of the center of the disk is π£. The disk then strikes a hurdle of height 3π 20 at point S. During the impact, there is no rebound or slip at S and no impulse from the surface PQ. The magnitude of the velocity of the center of the disk immediately after the impact is

Answer: D. 0.9π£
Marks: 2
A cylinder made of rubber (length = L and diameter = d) is inserted in a rigid container as shown in the figure. The rubber cylinder fits snugly in the rigid container. There is no wall friction. The modulus of elasticity of the rubber is E and its Poissonβs ratio is Ξ½. The cylinder is subjected to a small uniform pressure π as shown in the figure. The resulting axial strain (ππ§π§) is

Answer: C. β π πΈ[(1 + Ξ½)(1 β2Ξ½) (1 βΞ½) ]
Marks: 2
The state of stress at the critical location in a structure is ππ₯π₯ = 420 MPa, ππ¦π¦ = 100 MPa, ππ§π§= ππ₯π¦ = ππ¦π§= ππ§π₯= 0. The yield stress of the material in uniaxial tension is 400 MPa. Select the correct statement among the following.
Answer: C. The structure is unsafe by Tresca (maximum shear stress) theory and safe by von-Mises (distortion energy) theory.
Marks: 2
The figure shows a column of rectangular cross section 100 mm Γ 80 mm. It carries a load of 60 kN at a point 30 mm from the edge ππ. The values of stress component ππ§π§ on surfaces πππβ²πβ² and ππ π β²πβ², at points far away from both ends of the column, are respectively

Answer: D. 13.13 N/mm2 (Compressive) and 1.88 N/mm2 (Compressive)
Marks: 2
Consider an electric pole with dimensions as shown in the figure. Let the end R be subjected to a vertical force F. The flexural rigidity of both vertical and horizontal bars is EI. Neglect the axial deflection of the vertical bar, and all effects of self-weight. The vertical deflection at end R is

Answer: A. 7πΉπΏ3 3πΈπΌ
Type: MSQ | Marks: 2
A uniform cantilever beam has flexural rigidity πΈπΌ and length πΏ. It is subjected to a concentrated force πΉ and moment π= 2πΉπΏ at the free end as shown. The deflection (πΏ) at the free end is

Answer: C. 4πΉπΏ3 3πΈπΌ
Type: NAT | Marks: 2
A steel ball of mass π = 10 kg is suspended from the ceiling of a moving carriage by two inextensible strings making 60Β° with the horizontal as shown. The carriage has an acceleration π such that the tension in the string on the right is double the tension in the string on the left. Take the acceleration due to gravity (g) as 10 m/s2. The acceleration π (in m/s2) is______(rounded off to one decimal place).

Answer: 1.8 to 2.0
Type: NAT | Marks: 2
A block of mass π= 10 kg is lying on an inclined plane PQ. The mass is restrained from sliding down the inclined plane by a force πΉ. The coefficient of friction between the block and the inclined plane is 0.3. Take the acceleration due to gravity as 10 m/s2. The smallest force πΉ (in N) required to prevent the block from sliding down is______(rounded off to one decimal place).

Answer: 23.0 to 25.0
Type: NAT | Marks: 2
A spherical rigid ball of mass 10 kg is moving with a speed of 2 m/s in the direction shown. The ball collides with a rigid frictionless wall and rebounds at an angle πΌ with a speed of π£, as shown. The coefficient of restitution is 0.9. The angle πΌ (in degrees) is______(rounded off to one decimal place).

Answer: 57.0 to 58.0
Type: NAT | Marks: 2
A thin steel plate is loaded in the x-y plane as shown in the figure. Take the Poissonβs ratio of steel to be 0.3 and the modulus of elasticity of steel to be 200 GPa. The strain along the π§-direction is ππ§π§= β3 Γ 10β4. The value of ππ¦π¦ (in MPa) is______(rounded off to one decimal place).

Answer: 79.5 to 80.5
Type: NAT | Marks: 2
A composite rod made of steel and copper is fixed immovably at its ends as shown in the figure. The length of each portion of the rod is 1 m as shown. The cross-sections of both portions are the same. The moduli of elasticity of steel and copper are 200 GPa and 100 GPa, respectively. The coefficients of thermal expansion of steel and copper are 12 Γ 10β6 /β and 18 Γ 10β6 /β, respectively. The composite rod is initially stress free. Then, the temperature of the composite rod is increased by 100 β. The magnitude of axial stress (in MPa) developed in the steel rod is______(rounded off to one decimal place).

Answer: 199.0 to 201.0
Type: NAT | Marks: 2
A slender uniform elastic rod of length 1 m and of solid circular cross-section of diameter 50 mm is originally straight. It is then loaded by equal and opposite end moments as indicated in the figure. The resulting lateral displacement of the mid-point of the rod is 10 mm (displacements are exaggerated in the figure). The maximum longitudinal strain in the rod is π Γ 10β3, where π is______(rounded off to one decimal place).

Answer: 1.9 to 2.1
Type: NAT | Marks: 2
Consider a solid cylindrical shaft and a hollow cylindrical shaft. Both shafts are axisymmetric and elastic, and have the same cross-sectional area. The hollow shaft has an outside diameter of 150 mm and an inside diameter of 120 mm. When both the shafts are twisted by the same twisting moment, the ratio of maximum shear stress developed in the hollow shaft (πβ) to maximum shear stress developed in the solid shaft (ππ ) will be______(rounded off to three decimal places).
Answer: 0.350 to 0.380
Marks: 1
A The number of properties required to fix the state of a system is given by βstate postulateβ. R The state of a simple compressible system is completely specified by two independent, intensive properties. About the statements A and R applied to a single-phase system,
Answer: D. Both A and R are correct.
Marks: 1
Which of the following is an extensive property of a system?
Answer: D. Total mass
Marks: 1
A tank of volume V contains homogeneous mixture of two ideal gases, A and B at a temperature T and a pressure P. The mixture contains nA moles of gas A and nB moles of gas B. If PA and PB are the partial pressures of gas A and gas B, respectively, then
Answer: A. ππ΄= ππ΄ ππ΄+ ππ΅ π, ππ΅= ππ΅ ππ΄+ ππ΅ π
Marks: 1
If an ideal air-standard Otto cycle and an ideal air-standard Diesel cycle operate on the same compression ratio, then the relation between the thermal efficiencies (Ξ·th) of the cycles is
Answer: B. ππ‘β,ππ‘π‘π> ππ‘β,π·πππ ππ
Marks: 1
The following statements are given: (i) The third law of thermodynamics deals with the entropy of a substance at the absolute zero temperature. (ii) Entropy of any non-crystalline structure is zero at absolute zero temperature. (iii) At the absolute zero temperature, the crystal structure has maximum degree of order. (iv) The thermal energy of the substance at absolute zero temperature is maximum. The correct option describing these statements is
Answer: C. Both (i) and (iii) are correct
Marks: 1
Adiabatic bulk modulus of a substance is defined as
Answer: D. βπ£(ππ ππ£) π
Type: NAT | Marks: 1
An insulated rigid closed tank of 2 m3 internal volume contains saturated liquid- vapor mixture of water at 200 β. The quality of the mixture is 0.75. The mass of the mixture in the tank is ____________ kg (rounded off to one decimal place). Use the following data for water: At 200 β: vf = 0.001156 m3/kg, vfg = 0.12620 m3/kg, vg = 0.12736 m3/kg
Answer: 20.5 to 21.5
Type: NAT | Marks: 1
A rigid closed tank contains 2 kg of an ideal gas at 500 kPa and 350 K. A valve is opened, and half of the mass of the gas is allowed to escape. Then the valve is closed. If the final pressure in the tank is 300 kPa, the final temperature in the tank is ____________ K (in integer).
Answer: 420
Type: NAT | Marks: 1
Air at 400 K and 200 kPa is heated at constant pressure to 600 K. Assuming that the internal energy is a function of temperature only, the magnitude of change in internal energy during this process is ____________ kJ/kmol (rounded off to one decimal place). Use the following data: Molar specific heat of air at constant volume: πΜ π£ (kJ/kmol-K) = π+ ππ+ ππ2 where π is temperature in K, π = 19.686 kJ/kmol-K, π = 0.002 kJ/kmol-K2 and π= 0.5 Γ 10β5 kJ/kmol-K3.
Answer: 4389 to 4392
Marks: 2
A rigid closed tank having a volume of 2 m3 contains 0.1 m3 of saturated liquid water and 1.9 m3 of saturated water vapor at 100 kPa. Heat is transferred to the tank until the final tank pressure reaches 2 MPa. Following data for water is given: At 100 kPa: vf = 0.001043 m3/kg, vg = 1.694 m3/kg, uf = 417.33 kJ/kg, ug = 2506.06 kJ/kg At 2 MPa: vf = 0.001177 m3/kg, vg = 0.09963 m3/kg, uf = 906.42 kJ/kg, ug = 2600.26 kJ/kg The magnitude of heat transfer in this process is
Answer: D. 77470 kJ
Marks: 2
An ideal Diesel cycle has a compression ratio of 20 and cut-off ratio of 1.5. At the beginning of the compression stroke, air is at 100 kPa, 300 K. Use the cold-air-standard assumptions with property value cp = 1.005 kJ/kg-K. Assume cp / cv = 1.4. For this cycle, the net work output per unit mass is
Answer: A. 335 kJ/kg
Marks: 2
A 5 kg metal block (cp = 0.5 kJ/kg-K) at 373 K is submerged into 10 kg of water (cp = 4.2 kJ/kg-K) at 293 K in an insulated rigid container without spilling. Assuming thermal equilibrium is reached, the approximate entropy change of the universe is
Answer: B. 0.073 kJ/K
Marks: 2
Match the following: Thermodynamic function/equation Expression A1 Helmholtz function (a) B1 ( d dπ(ln π)) π ππ‘ = βπββπ π π2 A2 Gibbs function (g) B2 π’βππ A3 T-ds equation B3 dπ’= πdπ βπdπ£ A4 Clapeyron-Clausius equation B4 ββππ .
Answer: C. A1βB2, A2βB4, A3βB3, A4βB1
Type: NAT | Marks: 2
A piston-cylinder device initially contains 1 m3 of air at 200 kPa and 25 β. Air expands at constant pressure while a heater of 250 W is switched on for 10 minutes. There is a heat loss of 4 kJ during this process. Assuming air as an ideal gas, the final temperature of air is ____________ β (rounded off to one decimal place). Use the following data for air: R = 0.287 kJ/kg-K, cp = 1.005 kJ/kg-K
Answer: 85.0 to 88.0
Type: NAT | Marks: 2
Steam at 2 MPa and 300 β steadily enters a nozzle of inlet diameter of 20 cm. Steam leaves the nozzle with a velocity of 300 m/s. The mass flow rate of steam through the nozzle is 10 kg/s. Assume no work interaction and no change in potential energy. If the heat loss from the nozzle per kg of steam is 3 kJ, the exit enthalpy per kg of steam is ____________ kJ (rounded off to nearest integer). Use the following data for steam: At 2 MPa and 300 β: v = 0.12551 m3/kg, h = 3024.2 kJ/kg
Answer: 2975 to 2980
Type: NAT | Marks: 2
A rigid tank of 2 m3 internal volume contains 5 kg of water as a saturated liquid-vapor mixture at 400 kPa. Half of the mass of the saturated liquid in the tank is drained-off while maintaining constant pressure of 400 kPa in the tank. The final quality of the mixture remaining in the tank is ____________ (rounded off to two decimal places). Use the following data for water: At 400 kPa: vf = 0.001084 m3/kg, vfg = 0.46138 m3/kg, vg = 0.46246 m3/kg
Answer: 0.90 to 0.95
Type: NAT | Marks: 2
Consider a spark ignition engine which operates on an ideal air-standard Otto cycle. It uses a fuel which produces 44 MJ/kg of heat in the engine. If the engine requires 40 mg of fuel to produce 1 kJ of work output, then the compression ratio of the Otto cycle is ____________ (rounded off to two decimal places). For the entire cycle, use cp / cv = 1.4
Answer: 8.00 to 8.30
Type: NAT | Marks: 2
A refrigerator operates on an ideal vapor compression cycle between the pressure limits of 140 kPa and 800 kPa. The working fluid is the refrigerant R-134a. The refrigerant enters the compressor as saturated vapor at 140 kPa and exits at 800 kPa and 60 β. It leaves the condenser as a saturated liquid at 800 kPa. The coefficient of performance (COP) of the refrigerator is ____________ (rounded off to two decimal places). Use the following property data for R-134a: At 140 kPa: hf = 27.06 kJ/kg, hg = 239.19 kJ/kg At 800 kPa: hf = 95.48 kJ/kg, hg = 267.34 kJ/kg At 800 kPa and 60 β: h = 296.82 kJ/kg
Answer: 2.45 to 2.55
Type: NAT | Marks: 2
A steam power plant operates on a simple ideal Rankine cycle. The condenser pressure is 10 kPa and the boiler pressure is 5 MPa. The steam enters the turbine at 600 β. Mass flow rate of the steam is 50 kg/s. Neglecting the pump work, the net power output of the plant is ____________ MW (rounded off to one decimal place). Use the following property data for water: At 10 kPa: hf = 191.81 kJ/kg, hfg = 2392.82 kJ/kg, hg = 2584.63 kJ/kg sf = 0.6492 kJ/kg-K, sfg = 7.5010 kJ/kg-K, sg = 8.1502 kJ/kg-K At 5 MPa and 600 β: h = 3666.47 kJ/kg, s = 7.2588 kJ/kg-K
Answer: 67.3 to 69.3
Type: NAT | Marks: 2
In an air-conditioning system, air enters at 20 β and 30% relative humidity at a steady rate of 30 m3/min in a humidifier and it is conditioned to 25 β and 60% relative humidity. Assuming entire process takes place at pressure of 100 kPa, the mass flow rate of the steam added to air in the humidifier is ____________ kg/min (rounded off to three decimal places). Use the following property data: At 20 β and 25 β, saturation pressures of water are 2.3392 kPa and 3.1698 kPa, respectively. For air, R = 0.287 kJ/kg-K
Answer: 0.262 to 0.290
Type: NAT | Marks: 2
An office uses a heat pump to receive 500 kJ/day heat in winter to maintain its temperature at 300 K. The ambient temperature is 280 K. If the COP of the heat pump is 60% of its theoretical maximum value, the ratio of actual work input to the minimum theoretical work input to the heat pump is ____________ (rounded off to one decimal place).
Answer: 1.6 to 1.8
Type: NAT | Marks: 2
In a liquid-vapour phase change process, ( dπ dπ) π ππ‘at 100 Β°C for saturated water is 3750 Pa/K. If the resulting change in specific volume (π£πβπ£π) is 1.672 m3/kg, the enthalpy of vaporization (βππ) will be ____________ kJ/kg (in integer).
Answer: 2337 to 2341