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Full Mock Test & Solutions: GATE Engineering Sciences Mock Test - 3 (65 Questions)

You can boost your GATE Engineering Sciences 2026 exam preparation with this GATE Engineering Sciences Mock Test - 3 (available with detailed solutions).. This mock test has been designed with the analysis of important topics, recent trends of the exam, and previous year questions of the last 3-years. All the questions have been designed to mirror the official pattern of GATE Engineering Sciences 2026 exam, helping you build speed, accuracy as per the actual exam.

Mock Test Highlights:

  • - Format: Multiple Choice Questions (MCQ)
  • - Duration: 180 minutes
  • - Total Questions: 65
  • - Analysis: Detailed Solutions & Performance Insights
  • - Sections covered: General Aptitude, Engineering Mathematics (XE-A), Engineering Sciences (XE-B) & (XE-E)

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GATE Engineering Sciences Mock Test - 3 - Question 1

A sheet of transparent paper is folded in a specific way and a design is either cut or punched through it. Upon unfolding, the paper displays a pattern as illustrated in the provided answer figure. Select the correct answer figure shown below.

Detailed Solution: Question 1

Correct option C.

GATE Engineering Sciences Mock Test - 3 - Question 2

In a queue, Mr. X occupies the fourteenth position from the front, while Mr. Y is placed seventeenth from the back. Mr. Z is positioned exactly between Mr. X and Mr. Y. Given that Mr. X is in front of Mr. Y and there are a total of 48 individuals in the queue, how many individuals are situated between Mr. X and Mr. Z?

Detailed Solution: Question 2

The arrangement can be drawn as:

Position of Z will be after (14 + 8) = 22nd place.
Thus, Z is at 23rd.

There are 8 persons sitting between Mr. X and Mr. Z.

GATE Engineering Sciences Mock Test - 3 - Question 3

A committee of five members is to be formed from a group consisting of 7 men and 6 women, with the condition that the committee must include at least 3 men. How many different ways can this selection be made?

Detailed Solution: Question 3

We may have (3 men and 2 women) or (4 men and I women) or (5 men only)
Required number of ways

GATE Engineering Sciences Mock Test - 3 - Question 4

Given the matrix M = [[12 9i, -i], [i, 12 - 9i]], where i represents √-1, what is the inverse of the matrix M?

Detailed Solution: Question 4

Given matrix is:
M = [[12 + 9i, -i], [i, 12 - 9i]]

Determinant of M:
= |12 + 9i -i|
|i 12 - 9i|

= (12 + 9i)(12 - 9i) + i²
= (12² - 9²i²) + i²
= 225 - 1
= 224

∴ Inverse of M = M⁻¹ = (1 / |M|) × (adjM)
= (1 / 224) × [[12 - 9i, i], [-i, 12 + 9i]]

GATE Engineering Sciences Mock Test - 3 - Question 5

A scientist is employing the bisection method to determine the root of f(x) = 0. Initially, during an iteration, the lower and upper bounds for the root are designated as xl and xu. What would be the absolute relative approximate error in the estimated root value at the conclusion of the iteration?

Detailed Solution: Question 5

The correct answer is (C).

The absolute relative approximate error is:
|εₐ| = |(xₘⁿᵉʷ - xₘᵒˡᵈ) / xₘⁿᵉʷ|

where:
xₘⁿᵉʷ = (xₗ + xᵤ) / 2

If xm(old) = xl:

|εa| = |[((xl + xu) / 2) - xl] / [(xl + xu) / 2]|
= |[(xl + xu) - 2xl] / (xl + xu)|
= |(xu - xl) / (xu + xl)|

If xm(old) = xu:

|εa| = |[((xl + xu) / 2) - xu] / [(xl + xu) / 2]|
= |[(xl + xu) - 2xu] / (xl + xu)|
= |(xl - xu) / (xl + xu)|

The answer is the same whether xm(old) = xl or xu, as xm is exactly in the middle of xl and xu.

GATE Engineering Sciences Mock Test - 3 - Question 6

Consider the following two complex numbers:
Z1 = (7 / √3) 7i
Z2 = 9 (9√3)i

The angle of the product Z1Z2 (in degrees) is _____.

Detailed Solution: Question 6

Argument(Z₁) = θ₁ = tan⁻¹(7√3 / 7)
= tan⁻¹(tan 60°)
= 60°

Argument(Z₂) = θ₂ = tan⁻¹(9√3 / 9)
= tan⁻¹(tan 60°)
= 60°

Argument(Z₁Z₂) = Argument(Z₁) + Argument(Z₂)
= 60° + 60°
= 120°

GATE Engineering Sciences Mock Test - 3 - Question 7

y'' + 6y' + 9y = 0, y₁(x) = p(x), y₂(x) = q(x), y₁(0) = 1, y₁'(0) = -3, y₂(0) = 0, y₂'(0) = 1. Then,  at x = ln 3

Detailed Solution: Question 7


Now, as per the given conditions for y1 (x) and y2 (x)

*Answer can only contain numeric values
GATE Engineering Sciences Mock Test - 3 - Question 8

Consider An = 1 2 3 ... n and define Tn = (A2 / (A2 - 1)) × (A3 / (A3 - 1)) × (A4 / (A4 - 1)) × ... × (An / (An - 1)), where n ∈ N (n ≥ 2).

Determine the value of lim (n → ∞) Tn.


Detailed Solution: Question 8

An = n(n + 1) / 2

An - 1 = [n(n + 1) / 2] - 1 = (n² + n - 2) / 2
= [(n + 2)(n - 1)] / 2

An / (An - 1) = [n(n + 1)] / [(n + 2)(n - 1)]

Tn = [(n / (n - 1)) × ((n + 1) / (n + 2))]
= [(2/1) × (3/2) × (4/3) × ... × (n/(n - 1))] × [(3/4) × (4/5) × ... × (n + 1)/(n + 2)]

Tn = 3n / (n + 2)

lim (n → ∞) Tn = lim (n → ∞) (3n / (n + 2)) = 3

GATE Engineering Sciences Mock Test - 3 - Question 9

Evaluate the following statements:

  1. Streamlines represent the motion of each individual particle at a specific moment.
  2. Path lines depict the motion of a particular particle at every instant.
  3. The velocity component perpendicular to the streamline is consistently zero.
  4. In an unsteady flow, streak lines are also aligned with pathlines and streamlines.

Which of the statements listed above is/are CORRECT?

Detailed Solution: Question 9

Streamlines give the motion of each particle at a given instant. Path lines give the motion of a given particle at each instant. The component of velocity at right angle to the streamline is always zero.

GATE Engineering Sciences Mock Test - 3 - Question 10

A submarine is operating at a depth of 15 m beneath the surface of the ocean. If the submarine's speed is 16 km/hr, what is the gauge pressure at the front stagnation point (in kPa)?
Assume ρ_sea water = 1026 kg/m³

Detailed Solution: Question 10

The static pressure at a depth of 15 m below the sea surface is:

P (gauge) = ρgh
= 1026 × 9.81 × 15
= 150.976 kPa

Dynamic pressure = ρv² / 2
= (1026 × (16 × 10³ / 3600)²) / 2
= 10.133 kPa

Stagnation pressure = 150.976 + 10.133 = 161.109 kPa

*Answer can only contain numeric values
GATE Engineering Sciences Mock Test - 3 - Question 11

A model of a canal with a scale of 1/10 is constructed to analyze wave motion. In this model, a wave takes 10 seconds to cover a specific distance. The duration for the wave to traverse the equivalent distance in the actual prototype is ___ × 10¹/² s.


Detailed Solution: Question 11

In free surface flows, the significant dimensionless number is Froude number.

vp / √(glp) = vm / √(glm)
⇒ vp / vm = √(lp / lm) = 10(1/2)

velocity = distance / time

∴ tp = tm × (lp / lm) × (vm / vp)
= 10 × 10 × (1 / √10)
= 10 × √10
= 10 × 10(1/2) s

GATE Engineering Sciences Mock Test - 3 - Question 12

The kinematics of fluid flow in vector notation can be expressed through the following statements:

  1. The divergence is a mathematical operator that operates on a vector function and is denoted as . The outcome of this operation is always a scalar.

  2. The divergence indicates the flux that originates from any point within the specified vector function, effectively describing the rate of loss of a particular quantity.

  3. The curl is a mathematical operator that functions on a vector function and is represented as . The result of this operation is consistently a vector and denotes the infinitesimal rotation of a vector function.

  4. The Laplacian is a mathematical operator applied to a scalar function and is expressed as ∇²f. Its result is always a scalar and signifies the divergence of the gradient of a scalar function.

Which of the statements above is/are accurate?

Detailed Solution: Question 12

The divergence is a mathematical operator that acts on a vector function and is written as . The result is always a scalar.

The divergence represents the flux emanating from any point of the given vector function, essentially, a rate of loss of a specific quantity.

The curl is a mathematical operator that acts on a vector function and is written as . The result is always a vector. The curl represents the infinitesimal rotation of a vector function.

The Laplacian is a mathematical operator that acts on a scalar function and is written as ∇²f. The result is always a scalar. It represents the divergence of the gradient of a scalar function.

GATE Engineering Sciences Mock Test - 3 - Question 13

A uniform cylinder with a length of L and a mass of M, which has a cross-sectional area A, is suspended vertically from a fixed point using a massless spring. At its equilibrium position, the cylinder is half submerged in a liquid with a density of σ. What is the extension xo of the spring when the cylinder is in equilibrium?

Detailed Solution: Question 13

Let xo be the extension of the spring in the equilibrium position.
From FBI) of cylinder in equilibrium.


*Answer can only contain numeric values
GATE Engineering Sciences Mock Test - 3 - Question 14

The drag coefficient for an aircraft is expressed by the equation:

CD = (2FD) / (ρV2L2). Given that the drag force acting on a model airplane tested at sea level is 0.3 N, and that the speed of the actual prototype is 20 times greater than that of the model at an altitude of 3 km, with the length of the prototype being 15 times that of the model. Calculate the drag force acting on the prototype (in kN).
Use ρprototype = 0.9092 kg/m3 at an altitude of 3 km and ρmodel = 1.225 kg/m3.


Detailed Solution: Question 14

The requirement is CDprototype = CDmodel

⇒ (2FD / ρV²L²)p = (2FD / ρV²L²)m

⇒ (FD)p = (FD)m × (ρp / ρm) × (Vp / Vm)² × (Lp / Lm

= 0.3 × (0.9092 / 1.225) × (20Vm / Vm)² × (15Lm / Lm

= 20.04 × 10³ N

= 20 kN

*Answer can only contain numeric values
GATE Engineering Sciences Mock Test - 3 - Question 15

A source q is determined from the wall while fluid flow is directed towards the wall. The stream function is given by ψ = (4xy 80) m²/s, where x and y are measured in meters. The stagnation point is located along the y-axis. The value of d (in m) is __________. (Round off to three decimal places)


Detailed Solution: Question 15

We consider ideal fluid flow. Here, x = r cosθ and y = r sinθ. Then in terms of r and θ coordinates:

ψ = 4(r cosθ)(r sinθ) + 80
ψ = 2r² sin2θ + 80 ...(1)

The velocity components are:

vr = (1/r)(∂ψ/∂θ) = (1/r)[2r²(2 cos2θ) + 8] = (1/r)(4r² cos2θ + 8)

vθ = -(∂ψ/∂r) = -(4r sin2θ)

At stagnation point P, it is required that these velocity components are equal to zero.

vθ = -4r sin2θ = 0
sin2θ = 0 (since r ≠ 0)
2θ = 0, π rad
θ = 0, π/2 rad

θ = π/2 rad is chosen as it gives the direction r of the stagnation point.

vr = (1/r)(4r² cos2θ + 8) = 0
∴ 1/r ≠ 0, then 4r² cos2θ + 8 = 0

Substituting θ = π/2 rad and r = d into this equation:

4d² cos[2(π/2)] + 8 = 0
d = √2 m

*Answer can only contain numeric values
GATE Engineering Sciences Mock Test - 3 - Question 16

A building with a flat roof is situated 20 m away from the center of a tornado. This building lies within the tornado's free vortex, where the wind speed reaches 20 m/s at a distance of 40 m from the center. The air density is given as pa = 1.20 kg/m3. Assume a steady ideal fluid flow and that elevation changes can be neglected. What is the magnitude of the uplift pressure on the roof in __________Pa?


Detailed Solution: Question 16

Since the tornado is a free vortex, its velocity components are given by

It is required that at r = 40m,V =20m/s
thus,

20 = k/40;

⇒ k = 800 m2/s

then


Since free vortex is irrotational flow, Bernoulli's equation can be applied between two points on the different streamlines, such as two points on two circular streamlines of radius r = ∞ and r = 20 m. At r = ∞ , V = 0 and P = 0


The magnitude of uplift pressure on the root is = 960 Pa 

*Answer can only contain numeric values
GATE Engineering Sciences Mock Test - 3 - Question 17

Two immiscible liquids are positioned between two infinite parallel plates separated by a distance of 2h, with each fluid layer having a thickness of h. The dynamic viscosity of the fluid on the upper side is three times that of the fluid on the lower side. With the lower plate held stationary and the upper plate moving at a constant speed of U = 6.1 m/s, the pressure gradient in the flow direction is zero. What is the velocity at the interface, in m/s? Assume laminar flow and round your answer to two decimal places.


Detailed Solution: Question 17

Applying this to fluid 1 (lower fluid) and fluid 2 (upper fluid), integrating twice yields
u= c1.y + c2
u2 = c3 x y+ c4 

We need four BCs. Three are obvious y = 0, u₁ = 0, y = h, u₁ = u₂, y = 2h, u₂ = U
The fourth BC comes from the fact that the stress at the interface generated by each fluid is the same
y = h


Using these four BCs 0 = c₂, c₁ x h + c₂ = c₃ x h + c₄, U = c₃ x 2h + c₄, μ₁ x c₁ = μ₂ x c₃
Hence c₂ = 0
From the 2nd and 3rd equations c₁ × h − U = −c₃ x h and μ₁ x c₁ = μ₂ x c₃
Hence c₁ x h − U = −c₃ × h = (μ₁/μ₂) x h x c₁


Hence for fluid 1 (we do not need to complete the analysis for fluid 2

*Answer can only contain numeric values
GATE Engineering Sciences Mock Test - 3 - Question 18

A liquid trapped between two plates that are moving exhibits a linear velocity profile. Given that the pressure at the upper surface of the lower plate is 600 N/m2, what is the pressure at the lower surface of the upper plate (in kPa)?

Assume ρ = 1.2 × 103 kg/m3.


Detailed Solution: Question 18

From geometry, the x component of viscosity is:

(u - 0.2) / y = (1.2 - 0.2) / 0.01
u = (100y + 0.2) m/s

The velocity distribution is directed along the x-axis, v = 0.

∂v/∂x = 0; ∂u/∂y = ∂(100y + 0.2)/∂y = 100 m/s

wz = (1/2)(∂v/∂x - ∂u/∂y) = (1/2)(0 - 100) = -50 rad/s

wz ≠ 0 ⇒ Rotational flow

Applying Euler equation along the x-axis:

-(1/ρ)(∂P/∂x) = u(∂u/∂x) + v(∂u/∂y) ...(1)

-(1/ρ)(∂P/∂x) = u × 0 + 0 × (100)

⇒ -(1/ρ)(∂/∂x)[-ρgy + f(x)] = 0

⇒ ∂[f(x)]/∂x = 0

Integrating with respect to x:

f(x) = c
P = -ρgy + c

At point B, y = 0 and P = 600 N/m²:
600 = -1.2 × 10³ × 9.81 × 0 + c
c = 600 N/m²

And P = -ρgy + 600

At point A, y = 0.01 m:
PA = -1.2 × 10³ × 9.81 × 0.01 + 600
PA = 482.28 N/m²

GATE Engineering Sciences Mock Test - 3 - Question 19

You work as a Scientist at ISRO. A meteorite recently enters the upper atmosphere at a speed of 3000 m/s, where the atmospheric pressure measures 0.1 atm and the temperature is −40°C. Estimate the temperature of the air immediately in front of the meteorite, assuming no heat transfer occurs during this adiabatic stagnation process. Use Cp of air = 1.293 kJ/kgK and consider the specific heat to be constant.

Detailed Solution: Question 19

*Multiple options can be correct
GATE Engineering Sciences Mock Test - 3 - Question 20

Examine the application of the Clapeyron equation:

Which of the statements listed above is(are) accurate?

Detailed Solution: Question 20

*Answer can only contain numeric values
GATE Engineering Sciences Mock Test - 3 - Question 21

A container depicted in the figure contains two sections at varying pressures. The pressure gauges A and B indicate 6 bar gauge and 4 bar gauge, respectively. The barometric pressure is 760 mm of Hg. What will be the reading at gauge C in ________ bar gauge? Consider that 760 mm corresponds to 1.013 bar.


Detailed Solution: Question 21

∵ Y − 1.013 = reading on gauge A = 6 bar
∵ Y = 7.013 bar
∵ (Y − X) = 4 bar = reading on gauge B
∵ X = 3.013 bar
∵ X − 1.013 = Reading on gauge C
= 2.0 bar gauge

*Multiple options can be correct
GATE Engineering Sciences Mock Test - 3 - Question 22

Below are Maxwell's relations; which of the following statements are accurate?

Detailed Solution: Question 22

GATE Engineering Sciences Mock Test - 3 - Question 23

Air is moving uniformly through an insulated duct. The pressure and temperature readings of the air at two locations, A and B, are provided below. It is assumed that for air, the specific heat cp is constant at 1.005 kJ/kg.K, h = cpT, and v/T = 0.287/p, where P, v, and T denote pressure (in kPa), specific volume (m3/kg), and temperature (in K), respectively.

Select the correct statement.

Detailed Solution: Question 23


GATE Engineering Sciences Mock Test - 3 - Question 24

One ton of liquid water at 65°C is brought into a well-insulated and well-sealed 3m x 4m x 7m room initially at 22°C and 100 kPa. Assuming constant specific heats for both the air and water at room temperature, the exergy of destruction is when T = 10°C.

Detailed Solution: Question 24


Mass of air in the room


by energy Balance

GATE Engineering Sciences Mock Test - 3 - Question 25

A piston-cylinder assembly containing warm air is positioned horizontally as illustrated in the figure. The air undergoes a slow cooling process, reducing its volume from an initial value of 0.003 m³ to a final value of 0.002 m³. Throughout this process, the spring applies a force that decreases linearly from an initial force of 900 N to a final force of zero. The atmospheric pressure is 100 kPa, and the area of the piston face measures 0.018 m². Assume that friction between the piston and the cylinder wall is negligible for the air. What is the amount of work done?

Detailed Solution: Question 25

The initial and final pressures of the air are determined from a free-body diagram of the piston, as follows PA = PatmA + Fspring

Initially Fspring = 900 N, so that the initial pressure becomes

 

Finally, Fspring = 0, so the final pressure becomes P₂ = 100 kPa

Now, the work is evaluated by using the following curve:

So, W = ½ (250)(0.001 kJ) = 0.125 kJ = 125 J

GATE Engineering Sciences Mock Test - 3 - Question 26

Consider three identical objects with temperatures of 200K, 250K, and 540K, each having an internal energy described by the equation 8.4 x T kJ (where T is the temperature in K). If these objects are combined and allowed to reach a common final temperature, what is the maximum possible internal energy change in kJ?

Detailed Solution: Question 26

Let final temperature = T

Heat removed,
Q₁ = C(200 − T),
Q₂ = C(250 − T),
Q₃ = C(540 − T),

ΔU = 8.4(200 + 250 + 540 − 3T) = 8316 − 25.2T

*Answer can only contain numeric values
GATE Engineering Sciences Mock Test - 3 - Question 27

A cylinder of volume 1 m³ contains a mixture of CO₂ (20% mol) and O₂ (80% by mol) at 100 kPa and 300 K. This cylinder is connected to a 1 MPa pressure line carrying N₂ at 300 K. The cylinder is filled isothermally till the pressure of the gas mixture inside it becomes 500 kPa, and then the filling is stopped. The amount of N₂ gas that has entered the cylinder is ________ (in mole, 2 decimal places). The universal gas constant is 8.3145 J/(mol·K).


Detailed Solution: Question 27


Volume = 1 m3
Mole of Co2 , n1= 0.2 n
Where n is total number of total number of mole of mixture (CO2 + O2 )
Mole of O2, n2 = 0.8 n
Initial, P = 100 kPa
Initial, T = 300 K
Final pressure, P2 = 500 kPa, Temperature = 300 K
Assume mole of N2 as n3
From ideal gas equation

*Answer can only contain numeric values
GATE Engineering Sciences Mock Test - 3 - Question 28

A system experiences a cycle made up of the three processes shown in the table. ΔE = ΔU+ΔKE+ΔPE, the total of a b c d is ______ kJ. All values are in kJ.


Detailed Solution: Question 28

Use the first law in the form Q − W = ΔE. Applied to process 1 → 2, we have
a − 100 − 100 = a = 200 kJ
Applied to process 3 → 1, there results
100 − d − 200 = d = 300 kJ

The net-work is then ΣW = W₁₂ + W₂₃ + W₃₁ = 100 − 50 + 300 = 350 kJ. The first law for a cycle demands that
ΣQ = ΣW200 + B + 100 = 350
∴ B = 50 kJ

Finally, applying the first law to process 2 → 3 proves
50 − (−50) = c
∴ −c = 100 kJ

Note that for a cycle ΣΔE = 0, this, in fact, could have been used to determine the value of c.

ΣΔE = 100 + c = 200 = 0
c = 100 kJ
a + b + c + d = 650 kJ

*Answer can only contain numeric values
GATE Engineering Sciences Mock Test - 3 - Question 29

In an ideal vapor compression refrigeration cycle, the specific enthalpy values of the refrigerant at different stages are provided as follows:

  • Condenser inlet: 1700 kJ/kg
  • Condenser outlet: 400 kJ/kg
  • Evaporator outlet: 1200 kJ/kg

If the power requirement of the compressor is 50 kW, what is the plant capacity in __ tons?


Detailed Solution: Question 29

*Answer can only contain numeric values
GATE Engineering Sciences Mock Test - 3 - Question 30

A turbine functions under steady flow conditions and receives steam at the following parameters: pressure of 1.2 MPa, temperature of 188°C, enthalpy of 2785 kJ/kg, a velocity of 33.3 m/s, and an elevation of 3 m. The steam exits the turbine with the following characteristics: pressure of 20 kPa, enthalpy of 2512 kJ/kg, a velocity of 100 m/s, and an elevation of 0 m. There is heat loss to the surroundings at a rate of 0.29 kJ/s. Given that the steam flow rate through the turbine is 0.42 kg/s, calculate the power output of the turbine (in kW). Assume g = 9.81 m/s².


Detailed Solution: Question 30

p₁ = 1.2 MPa, p₂ = 20 kPa
T₁ = 188°C = 461 K
h₁ = 2785 kJ/kg, h₂ = 2512 kJ/kg
V₁ = 33.3 m/s, V₂ = 100 m/s
Z₁ = 3 m, Z₂ = 0

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