(SEM III) THEORY EXAMINATION 2021-22 ENGINEERING MECHANICS

This is the B.Tech Semester III examination paper for the subject Engineering Mechanics (KOE031), carrying 100 marks with a duration of 3 hours.
The paper tests fundamental and applied concepts of statics, dynamics, friction, trusses, beams, moments of inertia, kinematics, kinetics, bending, torsion, and related mechanical principles essential for engineering students.

The question paper is divided into three major sections – A, B, and C, progressively covering basic definitions, analytical problem solving, and long engineering calculations.

SECTION A – Short Conceptual Questions (20 Marks)

This section includes 10 questions of 2 marks each, focused on core fundamentals:

Collinear vs concurrent forces

Limiting angle of friction

Truss definition and types

Types of loads and supports in beams

Mass moment vs area moment of inertia

Types of motion

D’Alembert’s principle with example

Longitudinal and lateral strain

Pure bending in beams

Shaft definition and torsional rigidity

This section tests the student’s base understanding of mechanical concepts.
 

SECTION B – Analytical & Numerical Problem Solving (30 Marks)

Students must attempt any three out of five 10-mark questions. Topics include:

Resultant of four tangential forces on a circular body (diagram on page 1)

Shear force and bending moment diagram of a loaded beam

Centroid of remaining area after cutting a circular hole from a plate

Motion of a car skidding with friction — speed calculation

Total extension of a bar under multiple loads

This section emphasizes mechanics calculations, force systems, centroid analysis, friction-based motion, and deformation analysis.
 

SECTION C – Long, Application-Oriented Questions (50 Marks)

There are five main questions, each with two options, and students must attempt one part from each.

Q3 – Friction & Equilibrium

Ladder equilibrium with man climbing—distance before slipping

OR reactions on cylindrical rollers inside a cup

Q4 – Trusses & Beams

Forces in truss members EF, FC, CB

OR SFD & BMD for a beam + maximum bending moment + point of contraflexure

Q5 – Moments of Inertia

Moment of inertia of an L-section about centroidal axis (diagram on page 4)

OR expression for mass moment of inertia of a solid cone

Q6 – Kinematics & Dynamics

Using s = 9t + 7t² – 1.5t³ to find velocity, acceleration, etc.

OR two-body system with applied force, friction, tension & acceleration

Q7 – Bending & Torsion

Deriving bending equation, neutral axis, section modulus

OR design of shaft diameter for power transmission with torsion & twist limits

This section evaluates engineering-level problem solving, covering equilibrium, structural analysis, inertia, motion, bending theory, and torsional design.
 

OVERALL SUMMARY

The Engineering Mechanics (KOE031) paper thoroughly assesses:

Statics: forces, trusses, friction, equilibrium

Structural mechanics: beams, shear force, bending moment, pure bending

Dynamics: motion, acceleration, D’Alembert’s principle

Strength of materials: strain, deformation, torsion

Moments of inertia: area & mass MOI

Applied mechanical design problems

It blends theoretical understanding with diagram-based questions, numerical problems, real-life mechanical scenarios, and engineering calculations, ensuring a complete evaluation of students' foundational mechanical engineering skills.