PracticeVideosBlogFlashcardsEspañol
All Practice Exams

100+ Free ISRO Scientist Mechanical Practice Questions

Pass your ISRO Scientist/Engineer SC — Mechanical Engineering exam on the first try — instant access, no signup required.

✓ No registration✓ No credit card✓ No hidden fees✓ Start practicing immediately
100+ Questions
100% Free

Loading practice questions...

Same family resources

Explore More India PSU Engineering Recruitment Exams

Continue into nearby exams from the same family. Each card keeps practice questions, study guides, flashcards, videos, and articles in one place.

BEL Probationary Engineer exam

Practice Questions

Coal India Management Trainee (CIL MT)

Practice Questions

ISRO Scientist/Engineer — Civil

Practice Questions

ISRO Scientist/Engineer — Computer Science

Practice Questions

ISRO Scientist/Engineer — Electrical

Practice Questions

ISRO Scientist/Engineer (Electronics) exam

Practice Questions
2026 Statistics

Key Facts: ISRO Scientist Mechanical Exam

95 MCQs

Total questions in the written test

ISRO recruitment syllabus

120 min

Total duration of the examination

ISRO recruitment syllabus

−1/3 mark

Negative marking penalty for wrong answers

ISRO recruitment guidelines

₹750

Application fee (refundable to ₹250 or ₹0)

ISRO recruitment notification

80 / 20

Practice bank split: Part A Core / Part B Aptitude (100 total MCQs)

OpenExamPrep mock test design

ISRO Scientist Mechanical written test has 95 MCQs (80 core, 15 aptitude) in 120 minutes. Negative marking is -1/3. Fee of ₹750 is refunded to ₹250 or ₹0 upon appearing in the exam.

Sample ISRO Scientist Mechanical Practice Questions

Try these sample questions to test your ISRO Scientist Mechanical exam readiness. Each question includes a detailed explanation. Start the interactive quiz above for the full 100+ question experience with AI tutoring.

1Three coplanar concurrent forces P, Q, and R act at a point in equilibrium. The angle between P and Q is 120 degrees, and the angle between Q and R is 150 degrees. If the magnitude of force P is 100 N, what is the magnitude of force R?
A.50 N
B.86.6 N
C.100 N
D.173.2 N
Explanation: By Lami's Theorem, each force is proportional to the sine of the angle between the other two forces: P/sin(angle between Q and R) = R/sin(angle between P and Q). The angle between Q and R is 150° (opposite P) and the angle between P and Q is 120° (opposite R). Therefore R = P · sin(120°)/sin(150°) = 100 · (0.866/0.5) = 173.2 N.
2A block of weight 200 N rests on a rough inclined plane making an angle of 30 degrees with the horizontal. If the coefficient of static friction between the block and the plane is 0.4, what is the minimum force parallel to the incline required to prevent the block from sliding down?
A.30.7 N
B.69.3 N
C.100 N
D.169.3 N
Explanation: The component of the block's weight acting down the plane is W*sin(30°) = 200 * 0.5 = 100 N. The normal reaction is N = W*cos(30°) = 200 * 0.866 = 173.2 N. The maximum static friction force is f_max = mu * N = 0.4 * 173.2 = 69.28 N. Since W*sin(30°) (100 N) is greater than f_max (69.28 N), the block tends to slide down. To prevent it from sliding down, the minimum force F acting up the incline must satisfy: F + f_max = W*sin(30°). Thus, F = 100 - 69.28 = 30.72 N.
3A truss consists of members forming an equilateral triangle ABC with a horizontal base BC of length L. The truss is pinned at support B and rests on a roller support at C. A vertical downward load of 10 kN is applied at the top joint A. What is the force in member AB?
A.5 kN (Tension)
B.5.77 kN (Compression)
C.5.77 kN (Tension)
D.10 kN (Compression)
Explanation: Since the truss is symmetric and equilateral, the horizontal base BC forms a 60° angle with AB and AC. Reaction forces at B and C are equal to R_B = R_C = 10/2 = 5 kN (vertical). Considering joint B, the vertical equilibrium gives: F_AB * sin(60°) = R_B. Therefore, F_AB = 5 / sin(60°) = 5 / (sqrt(3)/2) = 10 / sqrt(3) = 5.77 kN. Since the reaction force acts upwards, member AB must push down on the joint, meaning member AB is in compression.
4A solid cylinder of mass M and radius R rolls down an inclined plane of angle theta without slipping. What is the acceleration of the center of mass of the cylinder?
A.(1/2) * g * sin(theta)
B.(2/3) * g * sin(theta)
C.(3/4) * g * sin(theta)
D.g * sin(theta)
Explanation: For a body rolling down an incline without slipping, the acceleration is given by a = g * sin(theta) / (1 + I / (M * R^2)), where I is the moment of inertia about the center of mass. For a solid cylinder, I = (1/2) * M * R^2. Substituting this in: a = g * sin(theta) / (1 + 1/2) = (2/3) * g * sin(theta).
5The position of a particle moving along a straight line is defined by s(t) = 2*t^3 - 9*t^2 + 12*t meters, where t is in seconds. At what time t is the velocity of the particle zero?
A.1 s and 2 s
B.1.5 s only
C.2 s and 3 s
D.Never
Explanation: Velocity is the first derivative of position with respect to time: v(t) = ds/dt = d(2*t^3 - 9*t^2 + 12*t)/dt = 6*t^2 - 18*t + 12. To find when velocity is zero, set v(t) = 0: 6*(t^2 - 3*t + 2) = 0 => (t - 1)*(t - 2) = 0. Therefore, the velocity is zero at t = 1 second and t = 2 seconds.
6A projectile is fired from the ground with an initial velocity of 50 m/s at an angle of 30 degrees to the horizontal. Neglecting air resistance and taking g = 10 m/s^2, what is the maximum height attained by the projectile?
A.31.25 m
B.62.5 m
C.93.75 m
D.125 m
Explanation: The maximum height H of a projectile is given by H = (u^2 * sin^2(theta)) / (2 * g). Here, u = 50 m/s, theta = 30°, and g = 10 m/s^2. Substituting the values: H = (50^2 * sin^2(30°)) / (2 * 10) = (2500 * 0.25) / 20 = 625 / 20 = 31.25 meters.
7Two spheres A and B of masses 2 kg and 4 kg respectively roll towards each other along a straight line on a frictionless surface with velocities of 6 m/s and 3 m/s. If the collision is perfectly elastic, what are their velocities after impact?
A.Sphere A: -6 m/s, Sphere B: 3 m/s
B.Sphere A: -3 m/s, Sphere B: 6 m/s
C.Sphere A: -6 m/s, Sphere B: 0 m/s
D.Sphere A: -4 m/s, Sphere B: 2 m/s
Explanation: Let velocity of A be u_A = 6 m/s and B be u_B = -3 m/s (opposite direction). In perfectly elastic collision (e = 1), both momentum and kinetic energy are conserved. Momentum conservation: m_A*u_A + m_B*u_B = m_A*v_A + m_B*v_B => 2*(6) + 4*(-3) = 2*v_A + 4*v_B => 12 - 12 = 0 => v_A + 2*v_B = 0 => v_A = -2*v_B. Coefficient of restitution: e = (v_B - v_A)/(u_A - u_B) => 1 = (v_B - v_A)/(6 - (-3)) => v_B - v_A = 9. Substituting v_A = -2*v_B: v_B - (-2*v_B) = 9 => 3*v_B = 9 => v_B = 3 m/s. Then, v_A = -2*(3) = -6 m/s.
8A small block of mass m is attached to a string passing through a hole in a frictionless horizontal table. The block is initially rotating in a circle of radius r_1 with an angular velocity omega_1. The string is then slowly pulled from below, reducing the radius of the circular path to r_2 = r_1 / 2. What is the new angular velocity of the block?
A.omega_1
B.2 * omega_1
C.4 * omega_1
D.8 * omega_1
Explanation: Since the force pulling the string is radial, it exerts no torque on the block about the hole. Thus, the angular momentum of the block about the hole is conserved. Initial angular momentum L_1 = m * v_1 * r_1 = m * r_1^2 * omega_1. Final angular momentum L_2 = m * r_2^2 * omega_2. Equating L_1 and L_2 gives: m * r_1^2 * omega_1 = m * r_2^2 * omega_2 => omega_2 = omega_1 * (r_1 / r_2)^2. Since r_2 = r_1 / 2, (r_1 / r_2) = 2. Thus, omega_2 = omega_1 * (2)^2 = 4 * omega_1.
9Which of the following represents the correct relationship between Young's Modulus (E), Shear Modulus (G), and Bulk Modulus (K) for an isotropic elastic material?
A.E = 9*K*G / (3*K + G)
B.E = 9*K*G / (K + 3*G)
C.E = 3*K*G / (9*K + G)
D.E = 3*K*G / (K + 9*G)
Explanation: The standard relationship between the elastic constants of an isotropic elastic material is E = 9*K*G / (3*K + G). This is derived from combining the equations E = 2*G*(1 + nu) and E = 3*K*(1 - 2*nu), where nu is Poisson's ratio.
10An element in a body is subjected to a state of pure shear stress of magnitude tau. What is the radius of Mohr's circle representing this state of stress?
A.tau / 2
B.tau
C.2 * tau
D.Zero
Explanation: Under pure shear stress tau, the principal stresses are sigma_1 = tau and sigma_2 = -tau. The center of Mohr's circle is at ( (sigma_x + sigma_y)/2, 0 ) = (0, 0). The radius of the Mohr's circle is given by R = sqrt( ((sigma_x - sigma_y)/2)^2 + tau_xy^2 ). Since sigma_x = sigma_y = 0 and tau_xy = tau, R = sqrt(0 + tau^2) = tau. Thus, the radius is equal to the magnitude of the pure shear stress.

About the ISRO Scientist Mechanical Exam

Practice for the ISRO Scientist/Engineer SC Mechanical exam. Our question bank includes exactly 100 exam-style practice questions with detailed explanations. Part A covers core mechanical topics: engineering mechanics, strength of materials, theory of machines, fluid mechanics, thermodynamics, heat transfer, manufacturing technology, and industrial engineering. Part B covers general aptitude, verbal and numerical reasoning. Every question provides detailed correct and wrong-answer explanations.

Assessment

The written test is a single 120-minute session containing two parts: Part A with 80 core Mechanical Engineering MCQs (1 mark each) and Part B with 15 Aptitude/Reasoning MCQs (20 marks total). One-third of marks are deducted for wrong answers.

Time Limit

120 minutes

Passing Score

50% marks in both parts combined for UR/OBC, and 40% for reserved categories

Exam Fee

₹750 (with fee refunds of ₹500 or ₹750 upon appearing in the exam) (Indian Space Research Organisation (ISRO))

ISRO Scientist Mechanical Exam Content Outline

10%

Engineering Mechanics

Free body diagrams, equilibrium, trusses, friction, kinematics and dynamics of particles and rigid bodies.

10%

Strength of Materials

Stress and strain, elastic constants, shear force and bending moment diagrams, bending and shear stresses, deflection of beams, torsion of shafts, columns, thin cylinders.

10%

Theory of Machines & Vibrations

Displacement, velocity and acceleration analysis of planar mechanisms, cams, gears and gear trains, flywheels, governors, balancing, free and forced single degree of freedom vibrations.

10%

Machine Design

Design for static and dynamic loading, failure theories, fatigue strength, S-N diagram, bolted, riveted and welded joints, shafts, gears, clutches, brakes, bearings.

10%

Fluid Mechanics & Turbo Machines

Fluid properties, manometry, buoyancy, forces on submerged bodies, fluid kinematics, Bernoulli's equation, flow through pipes, boundary layer, velocity triangles, Pelton wheel, Francis and Kaplan turbines, centrifugal pumps.

10%

Thermodynamics & Thermal Cycles

Thermodynamic systems and processes, laws of thermodynamics, entropy, availability and irreversibility, properties of pure substances, vapor and gas power cycles, IC engines.

10%

Heat Transfer

Modes of heat transfer, one-dimensional heat conduction, resistance concept, electrical analogy, unsteady heat conduction, fins, dimensionless parameters, free and forced convection, heat exchangers, radiative heat transfer.

10%

Manufacturing & Material Science

Structure and properties of engineering materials, phase diagrams, heat treatment, casting, forming, joining, machining, CNC machining, metrology, limits, fits and tolerances.

10%

Industrial & Operations Research

Production planning and control, inventory control, forecasting, PERT/CPM, linear programming, simplex method, transportation and assignment models.

10%

General Aptitude & Reasoning

Quantitative aptitude, logical reasoning, numerical series, verbal reasoning, coding-decoding, and general mental ability.

How to Pass the ISRO Scientist Mechanical Exam

What You Need to Know

  • Passing score: 50% marks in both parts combined for UR/OBC, and 40% for reserved categories
  • Assessment: The written test is a single 120-minute session containing two parts: Part A with 80 core Mechanical Engineering MCQs (1 mark each) and Part B with 15 Aptitude/Reasoning MCQs (20 marks total). One-third of marks are deducted for wrong answers.
  • Time limit: 120 minutes
  • Exam fee: ₹750 (with fee refunds of ₹500 or ₹750 upon appearing in the exam)

Keys to Passing

  • Complete 500+ practice questions
  • Score 80%+ consistently before scheduling
  • Focus on highest-weighted sections
  • Use our AI tutor for tough concepts

ISRO Scientist Mechanical Study Tips from Top Performers

1Focus heavily on core subjects like Strength of Materials, Thermodynamics, and Fluid Mechanics, which carry significant weight in Part A.
2Practice calculations without a calculator, as physical calculators are not permitted in the ISRO written examination.
3Revise key formulas and standard values, as speed and accuracy are crucial to completing 95 questions in 120 minutes.
4Ensure you spend time on Part B General Aptitude, which contributes 20% to the overall marks and is essential for qualifying.
5Solve previous years' ISRO Scientist Mechanical exam papers to understand the depth and typical questions asked.

Frequently Asked Questions

What is the exam pattern for the ISRO Scientist/Engineer SC Mechanical recruitment?

The written test comprises two parts: Part A containing 80 core Mechanical Engineering MCQs (1 mark each, 80 marks total) and Part B containing 15 Aptitude/Reasoning MCQs (20 marks total). The total exam duration is 120 minutes.

Is there negative marking in the ISRO Scientist Mechanical exam?

Yes, there is negative marking. For every incorrect answer, one-third (1/3) of the marks assigned to that question will be deducted. For Part A, it is 1/3 mark. For Part B, it is 1/3 of the respective question's marks.

How does the ISRO recruitment fee refund work?

The application fee is ₹750. However, upon actually appearing for the written examination, the fee is refunded: female candidates and SC/ST/PwBD/Ex-Servicemen receive a full refund of ₹750, while male candidates of General/OBC/EWS categories receive a refund of ₹500, making the net fee ₹250.

What are the eligibility criteria for the ISRO Scientist Mechanical exam?

Candidates must have a first-class B.E./B.Tech or equivalent degree in Mechanical Engineering with a minimum of 65% aggregate marks or a CGPA of 6.84/10. The maximum age limit is 28 years, with government-mandated relaxations for reserved categories.

Does this practice bank include calculation questions?

Yes, this mock bank includes typical ISRO-style calculation questions on thermodynamics, heat transfer, fluid mechanics, machine design, and strength of materials, as well as aptitude problems, all designed to be solvable within the exam time constraints.