Dynamics of Machinery Important Questions | Unit-wise R23 Exam Guide
Dynamics of Machinery involves understanding how forces act on machine components while they are in motion. This subject forms the base for machine design, engines, manufacturing systems, industrial machines, and automation. This blog provides Dynamics of Machinery important questions arranged unit-wise to make exam preparation smoother and more structured.
Dynamics of Machinery Important Questions for R23 JNTU Students (Unit-Wise)
Unit 1: Kinetics & Kinematics of Rigid Bodies
Key Theory Questions
Explain the concept of kinetics in the context of Dynamics of Machinery.
What is D’Alembert’s principle? Describe its significance.
Define work-energy principle and explain its applications.
What is impulse–momentum principle? How is it used in machinery analysis?
Define torque and angular momentum.
Explain dynamic equilibrium with examples.
What is the difference between linear and rotational motion?
Explain the concept of radius of gyration.
Describe the terms angular displacement, velocity, and acceleration.
What is the importance of free-body diagrams in Dynamics of Machinery?
Explain plane motion of a rigid body.
What is a mass moment of inertia and why is it important?
Define principle of virtual work.
Explain the concept of general plane motion.
Describe the difference between translation and rotation.
What is instantaneous center of rotation?
Explain kinetic energy of a rotating body.
What is the relation between torque and angular acceleration?
Describe Newton’s laws of motion in context of machine dynamics.
Explain rolling motion and its applications.
Numerical Focus Question
Find the angular acceleration of a disc subjected to torque.
Calculate the kinetic energy of a flywheel rotating at given RPM.
A body in translation accelerates from rest. Find the work done.
Compute mass moment of inertia of a solid cylinder.
Determine angular momentum of a rotating shaft.
Apply work-energy principle to find velocity of a slider.
Solve a problem using impulse–momentum relation.
Find acceleration of a point on a rotating link.
Compute torque required to accelerate a disc.
Solve general plane motion of a rigid body.
Unit 2: Balancing of Rotating & Reciprocating Masses
Key Theory Questions
What is balancing? Why is it important in Dynamics of Machinery?
Define static balancing and dynamic balancing.
Explain the balancing of rotating masses with examples.
Describe the concept of couple and resultant force.
What are the effects of unbalanced rotating masses?
Explain partial balancing in reciprocating engines.
What is primary and secondary balancing?
Describe balancing of multi-cylinder engines.
What are the consequences of poor balancing?
Explain torque fluctuation and turning moment diagram.
What is a hammer blow in locomotives?
Explain swaying couple and its impact.
Describe balancing in V-engines.
What is tractive force?
Explain firing order influence on balancing.
Numerical Focus Question
Balance a single rotating mass with two masses.
Calculate primary balancing for a reciprocating engine.
Determine unbalanced force in rotating system.
Solve balancing of four-mass system.
Compute swaying couple in locomotives.
Determine hammer blow.
Calculate secondary unbalanced forces.
Balance a multi-cylinder inline engine.
Find counterweights for rotating shafts.
Solve balancing of V-engine.
Unit 3: Governors
Key Theory Questions
What is a governor? Why is it used in machinery?
Explain the working principle of centrifugal governors.
What is isochronism in governors?
Describe hunting in governors.
What are sensitiveness, stability, and effort of a governor?
Explain Hartnell governor in detail.
What is equilibrium speed?
Describe controlling force curve.
What is the difference between governor and flywheel?
Explain load and lift in governors.
Describe the Porter governor.
Explain friction effects in governors.
What is power of governor?
State the purpose of governor springs.
Explain stability characteristics
Numerical Focus Question
Determine equilibrium speed of Porter governor.
Calculate lift for given radius change.
Solve sensitiveness for a governor.
Find effort and power of governor.
Solve controlling force curve values.
Determine radius of rotation at certain speed.
Compute forces acting on balls.
Solve Hartnell governor numerical.
Calculate operating speed range.
Determine height of centrifugal governor.
Unit 4: Gyroscopic Motion
Key Theory Questions
What is gyroscopic couple?
Explain gyroscopic effects on vehicles.
Describe the effect of gyroscopic couple on aircraft.
What is precession?
Explain effect of gyroscopic couple on ships.
Define angular momentum in gyroscopes.
What is the significance of gyroscopic effect in automobiles?
Explain the action of a disk in rotation.
Describe stability of two-wheelers due to gyroscopic action.
Discuss gyroscopic effect in turbines.
Numerical Focus Question
Calculate gyroscopic couple for rotating disc.
Solve precession angular velocity.
Determine gyroscopic effects on a car negotiating curve.
Compute gyroscopic couple acting on aircraft propeller.
Find stability condition for two-wheelers.
Solve gyroscopic reaction on ship turning.
Compute moment of a rotating rotor.
Calculate forces on turbine shaft.
Solve angular precession problems.
Determine effect of rotation on marine engines.
Unit 5: Mechanical Vibrations
Key Theory Questions
Define vibration and classify types of vibrations.
What is free vibration? Explain with examples.
Describe forced vibrations.
What is damping?
Explain resonance and its dangers.
What is natural frequency?
Describe torsional vibrations.
What is critical speed of shaft?
Explain vibration isolation.
What are vibration measuring instruments such as vibrometer, accelerometer?
Explain transmissibility.
Describe two-degree freedom systems.
What is logarithmic decrement?
Explain vibration absorbers.
Discuss whirling of shaft.
Numerical Focus Question
Calculate natural frequency of spring-mass system.
Solve damped vibration problem.
Determine resonance condition.
Calculate logarithmic decrement.
Solve forced vibration amplitude.
Find critical speed of rotating shaft.
Determine stiffness from vibration data.
Calculate transmissibility ratio.
Solve torsional vibration system.
Determine frequency of two-degree freedom system.
Preparation Tips for Dyanamics of Machinery
✔ Understand concepts before solving numericals
✔ Practice at least 10 numericals from each unit
✔ Draw diagrams clearly (governors, gyroscopes, balancing)
✔ Revise formulas daily (but avoid rote learning)
✔ Attempt previous year university papers
✔ Focus more on units: Balancing, Governors, Vibrations
✔ Use simple steps for long derivations
✔ Allocate 1 hour per day exclusively for numericals
Conclusion
Dynamics of Machinery is a scoring subject when you prepare unit-wise and practice numerical problems. This blog covered Dynamics of Machinery important questions in a clear, structured, and student-friendly way. Use these questions as your preparation roadmap and revise consistently for the best results.
