Gujarat Technological UniversitySummer 2023 examination

GTU 3151911 Dynamics of Machinery Summer 2023 Question Paper & PDF

B.E. · Mechanical Engineering · Semester 5 · Subject code 3151911
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Total
70 marks
To pass
23 marks (33%)
Duration
2.5 Hours 2:30 PM – 5:00 PM
Questions
5 with internal choice
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9 of 25 questions on this paper were also asked in other years. 7 more are types of question GTU sets again with new data. Each is marked below with the years it appeared.See all 21 repeated 3151911 questions, most asked first

Q.1

14 Marks
(a)
3 marksAsked in 3 of 4 papers
Explain the effect of gyroscopic couple on naval ship.

Also asked in Summer 2026 Q2a, Summer 2025 Q3b OR

(b)
4 marks
Explain the difference between piston effort, crank effort and crank-pin effort.
(c)
7 marksSame type asked in 3 of 4 papers

The three cranks of a three-cylinder locomotive are all on the same axle and are set at 120°. The pitch of the cylinders is 1 metre and the stroke of each piston is 0.6 m. The reciprocating masses are 300 kg for inside cylinder and 260 kg for each outside cylinder and the planes of rotation of the balance masses are 0.8 m from the inside crank. If 40% of the reciprocating parts are to be balanced, find the magnitude and the position of the balancing masses required at a radius of 0.6 m.

Also asked in Summer 2026 Q5c, Summer 2025 Q4c

Q.2

14 Marks
(a)
3 marksAsked in 3 of 4 papers
Define the terms:
i)magnification factor,
ii)force transmissibility,
iii)relative amplitude.

Also asked in Summer 2025 Q5a OR, Summer 2024 Q3b OR

(b)
4 marks
Explain the terms ‘fluctuation of energy’ and ‘fluctuation of speed’ as applied to

flywheels.

(c)
7 marks
Find the natural frequency of the given system given in the figure 2.1.

Figure 2.1

GTU Dynamics of Machinery (3151911) Summer 2023 Question 2(c) Diagram
(c)
7 marksSame type asked in 3 of 4 papers

In a slider crank mechanism, the length of the crank and connecting rod are 150 mm and 600 mm respectively. The crank position is 60° from inner dead center. The crank shaft speed is 450 r.p.m. (clockwise). Using analytical method, determine: 1. Velocity and acceleration of the slider, and 2. Angular velocity and angular acceleration of the connecting rod.

Also asked in Summer 2026 Q1b, Summer 2025 Q3c

Q.3

14 Marks
(a)
3 marks

Derive an expression of swaying couple for an uncoupled two-cylinder locomotive engine.

(b)
4 marksAsked in 2 of 4 papers
Explain the method of balancing of inline engines.

Also asked in Summer 2025 Q1c

(c)
7 marksSame type asked in 2 of 4 papers

Four masses P, Q, R and S as shown below are to be completely balanced. P Q R S Mass (Kg) --- 30 50 40 Radius (mm) 180 240 120 150 The planes containing masses Q and R are 300 mm apart. The angle between planes containing Q and R is 90°. Q and R make angles of 210° and 120° respectively with S in the same sense. Find:

1The magnitude and the angular position of mass P; and
2The position of planes P and S.

Also asked in Summer 2024 Q5c OR

(a)
3 marks
Derive an expression for time period of damped vibration.
(b)
4 marksAsked in 2 of 4 papers
Explain with neat sketch working of any one frequency measuring instrument.

Also asked in Summer 2025 Q5b

(c)
7 marksSame type asked in 3 of 4 papers

A vibratory body of mass 150 Kg supported on springs of total stiffness 1050 KN/m and has a rotating unbalance of 525 N at a speed of 6000 rpm. If the damping factor is 0.3, determine;

i)the amplitude caused by the unbalance,
ii)the transmissibility
iii)the actual force transmitted and its phase angle.

Also asked in Summer 2026 Q4c, Summer 2025 Q5c OR

Q.4

14 Marks
(a)
3 marksAsked in 3 of 4 papers
State the D’Alembert’s principle and explain any one application of it.

Also asked in Summer 2026 Q1a, Summer 2025 Q3b

(b)
4 marks

Explain the turning moment diagram of a four stroke cycle internal combustion engine.

(c)
7 marksSame type asked in 2 of 4 papers

A single cylinder double acting steam engine develops 150 kW at a mean speed of 80 r.p.m. The coefficient of fluctuation of energy is 0.1 and the fluctuation of speed is ± 2% of mean speed. If the mean diameter of the flywheel rim is 2 meter and the hub and spokes provide 5% of the rotational inertia of the flywheel, find the mass and cross-sectional area of the flywheel rim. Assume the density of the flywheel material made of cast iron as 7200 kg/m³.

Also asked in Summer 2025 Q3c OR

(a)
3 marksAsked in 2 of 4 papers
Define the terms:
i)Natural frequency,
ii)damping,
iii)mechanical vibrations

Also asked in Summer 2025 Q2a

(b)
4 marksAsked in 2 of 4 papers
Derive an expression for equation of motion of critically-damped system.

Also asked in Summer 2025 Q4b OR

(c)
7 marksSame type asked in 3 of 4 papers

Determine the damping constant of the particular viscous system for the following data; Amplitude of second cycle = 12 mm Amplitude of third cycle = 10.5 mm Spring constant = 800 N/m Weight on spring = 2 Kg.

Also asked in Summer 2026 Q2c, Summer 2026 Q2c OR, Summer 2024 Q2c

Q.5

14 Marks
(a)
3 marksAsked in 4 of 4 papers
Differentiate between static balancing and dynamic balancing.

Also asked in Summer 2026 Q5a, Summer 2025 Q1a, Summer 2024 Q2b

(b)
4 marksAsked in 3 of 4 papers
What do you understand by gyroscopic couple? Derive a formula for its magnitude.

Also asked in Summer 2026 Q2a, Summer 2025 Q3b OR

(c)
7 marksSame type asked in 4 of 4 papers

A four wheeled motor car of mass 2000 kg has a wheel base 2.5 m, track width 1.5 m and height of centre of gravity 500 mm above the ground level and lies at 1 metre from the front axle. Each wheel has an effective diameter of 0.8 m and a moment of inertia of 0.8 kg-m2. The drive shaft, engine flywheel and transmission are rotating at 4 times the speed of road wheel, in a clockwise direction when viewed from the front, and is equivalent to a mass of 75 kg having a radius of gyration of 100 mm. If the car is taking a right turn of 60 m radius at 60 km/h, find the load on each wheel.

Also asked in Summer 2026 Q2b, Summer 2025 Q2c, Summer 2024 Q4c, Summer 2024 Q4c OR

(a)
3 marks
State different ways of providing the damping and explain any one in detail.
(b)
4 marks
Derive an expression for torsionally equivalent shaft system.
(c)
7 marks

A vertical shaft is held between the long bearings and a disc is attached to the shaft at its mid-point. The center of gravity of the disc does not coincide with the axis of the shaft. The diameter of the shaft is 15 mm and the span of the shaft between two bearings is 1 meter. The mass of the disc is 10 Kg and the center of the gravity of the disc is 0.3 mm from the axis of the shaft. Take E = 200 GN/m² and permissible stress in the shaft material as 70 * 106 /m². Determine the critical speed of the shaft and the range of the speed over which it is unsafe to run the shaft.

More Dynamics of Machinery papers

Questions repeat across sessions. Working through two or three papers shows you which topics GTU asks most.

Summer 202670 marks · 5 questions · Solved
Summer 202570 marks · 5 questions
Winter 202470 marks · 5 questions
Summer 202470 marks · 5 questions

Other Semester 5 subjects

BE Mechanical

2151902
Theory of Machines
2151903
Fluid Power Engineering
2151908
Control Engineering
2151909
Heat Transfer

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About this paper

Official Gujarat Technological University (GTU) examination paper for Dynamics of Machinery (Summer 2023, B.E. · Mechanical Engineering, Sem 5). Features complete 70-mark regular & remedial examination pattern, official marking distribution across all 5 questions, and direct 1-click official PDF download.

Transcribed for student exam preparation from Gujarat Technological University official examination archives. Questions, syllabus guidelines, and curriculum marking schemes remain the intellectual property of Gujarat Technological University.

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