Gujarat Technological UniversitySummer 2025 examination

GTU 3141907 Fundamentals of Machine Design Summer 2025 Question Paper & PDF

B.E. · Mechanical Engineering · Semester 4 · Subject code 3141907
Download official PDFView PDF here
Share with your class
Total
70 marks
To pass
23 marks (33%)
Duration
2.5 Hours 10:30 AM – 1:00 PM
Questions
5 with internal choice
No solutions on this paper yetNeed them for your exam? Ask once. Papers that students ask for are solved first, and we aim to add them within 24 hours.

9 of 25 questions on this paper were also asked in other years. 3 more are types of question GTU sets again with new data. Each is marked below with the years it appeared.See all 10 repeated 3141907 questions, most asked first

Q.1

14 Marks
(a)
3 marksAsked in 2 of 2 papers
Define limits, fits and tolerance

Also asked in Summer 2026 Q2a

(b)
4 marks

Solve, A journal 25 mm in diameter supported in sliding bearings has a maximum end reaction of 2500 N. Assuming an allowable bearing pressure of 5 N/mm², find the length of the sliding bearing.

(c)
7 marksAsked in 2 of 2 papers
Develop spigot and socket cotter joint using step by step design procedure.

Also asked in Summer 2026 Q2c OR

Q.2

14 Marks
(a)
3 marksAsked in 2 of 2 papers
What is key? What are the different types of key?

Also asked in Summer 2026 Q4a

(b)
4 marks

State and explain the different theories of failures and its importance. Explain Distortion energy (von Mises) theory.

(c)
7 marks

Design and draw a cotter joint to support a load varying from 30 kN in compression to 30 kN in tension. The material used is carbon steel for which the following allowable stresses may be used. The load is applied statically. Tensile stress = compressive stress = 50 MPa ; shear stress = 35 MPa and crushing stress = 90 MPa.

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

Design a knuckle joint to transmit 150 kN. The design stresses may be taken as 75 MPa in tension, 60 MPa in shear and 150 MPa in compression.

Also asked in Summer 2026 Q2c

Q.3

14 Marks
(a)
3 marks
What is a coupling? Classify the couplings
(b)
4 marks
Explain the basic procedure for design of machine elements.
(c)
7 marksSame type asked in 2 of 2 papers

A vertical two start square threaded screw of a 100 mm mean diameter and 20 mm pitch supports a vertical load of 18 kN. The axial thrust on the screw is taken by a collar bearing of 250 mm outside diameter and 100 mm inside diameter. Find the force required at the end of a lever which is 400 mm long in order to lift and lower the load. The coefficient of friction for the vertical screw and nut is 0.15 and that for collar bearing is 0.20.

Also asked in Summer 2026 Q5b OR

(a)
3 marks
Explain the Hooke’s law with a neat sketch for ductile materials
(b)
4 marksAsked in 2 of 2 papers
Derive the equation for simple bending. Also state the assumptions in this derivation.

Also asked in Summer 2026 Q3b

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

The lead screw of a lathe has Acme threads of 50 mm outside diameter and 8 mm pitch. The screw must exert an axial pressure of 2500 N in order to drive the tool carriage. The thrust is carried on a collar 110 mm outside diameter and 55 mm inside diameter and the lead screw rotates at 30 r.p.m. Determine the power required to drive the screw; Assume a coefficient of friction of 0.15 for the screw and 0.12 for the collar.

Also asked in Summer 2026 Q5b OR

Q.4

14 Marks
(a)
3 marksAsked in 2 of 2 papers
Define the following terms:
i)Hooke’s law
ii)Poisson’s ratio
iii)Preferred series.

Also asked in Summer 2026 Q1b

(b)
4 marks
Explain :
1)Pitch
2)Lead
3)Nominal diameter
4)Core diameter for Power screw.
(c)
7 marks

A mild steel rod supports a tensile load of 50 kN. If the stress in the rod is limited to 100 MPa, find the size of the rod when the cross-section is 1. Circular, 2. Square, and 3. Rectangular with width = 3 × thickness.

(a)
3 marksAsked in 2 of 2 papers
Discuss torsion in solid shaft and hollow shaft.

Also asked in Summer 2026 Q4b

(b)
4 marksAsked in 2 of 2 papers

What do you mean by stress concentration? State the reasons for stress concentration and explain any two of the methods used for reducing it.

Also asked in Summer 2026 Q5b

(c)
7 marks

A hollow shaft of 40 mm outer diameter and 25 mm inner diameter is subjectedto a twisting moment of 120 N-m, simultaneously; it is subjected to an axial thrust of 10 kN and a bending moment of 80 N-m. Calculate the maximum compressive and shear stresses.

Q.5

14 Marks
(a)
3 marksAsked in 2 of 2 papers
How the hollow shafts are beneficial over the solid shaft?

Also asked in Summer 2026 Q4b

(b)
4 marks
What is endurance limit? Discuss the different factors affecting endurance limit
(c)
7 marks

45 mm diameter shaft is made of steel with a yield strength of 400 MPa. A parallel key of size 14 mm wide and 9 mm thick made of steel with a yield strength of 340 MPa is to be used. Find the required length of key, if the shaft is loaded to transmit the maximum permissible torque. Use maximum shear stress theory and assume a factor of safety of 2.

(a)
3 marksAsked in 2 of 2 papers
Define self-locking of power screw. Explain the condition for self-locking

Also asked in Summer 2026 Q5a OR

(b)
4 marks
Explain the different types of fits with neat sketch.
(c)
7 marks

A rectangular strut is 150 mm wide and 120 mm thick. It carries a load of 180 kN at an eccentricity of 10 mm in a plane bisecting the thickness as shown in Fig. Find the maximum and minimum intensities of stress in the section.

GTU Fundamentals of Machine Design (3141907) Summer 2025 Question 5 OR (c) Diagram

More Fundamentals of Machine Design papers

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

Preparing with friends?

Send this paper to your class group. Every question has its own link.

About this paper

Official Gujarat Technological University (GTU) examination paper for Fundamentals of Machine Design (Summer 2025, B.E. · Mechanical Engineering, Sem 4). 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.

ViewDownload PDF