Download GTU (Gujarat Technological University) BE/BTech (Bachelor of Engineering / Bachelor of Technology) 2018 Winter 5th Sem Old 151905 Machine Design I Previous Question Paper
1
Seat No.: ________ Enrolment No.___________
GUJARAT TECHNOLOGICAL UNIVERSITY
BE - SEMESTER ?V (OLD) EXAMINATION ? WINTER 2018
Subject Code:151905 Date: 07/12/2018
Subject Name: Machine Design - I
Time: 10:30 AM TO 01:00 PM Total Marks: 70
Instructions:
1. Attempt all questions.
2. Make suitable assumptions wherever necessary.
3. Figures to the right indicate full marks.
Q.1 (a) What do you mean by standardization? Explain role of preferred numbers in
standardization?
04
(b) What is Endurance Limit? Explain Design criteria with Solderberg?s line. 04
(c) Explain design of components for forging. 03
(d) Explain Manufacturing and assembly considerations in machine design 03
Q.2 (a) Define stress concentration factor. Explain methods for reducing stress
concentration with figure.
07
(b) A rotating bar made of steel 45C8 (Sut = 630 N/mm
2)
is subjected to a completely
reversed bending stress. The corrected endurance limit of the bar is 315 N/mm
2
.
Calculate the fatigue strength of the bar for a life of 90,000 cycles.
07
OR
(b) What is the importance of wear considerations in design? Explain the measures
to minimize the wear
07
Q.3 (a) Explain the following and state how can they be prevented? (i) Buckling of spring
(ii) Surge in springs
07
(b) Explain the different types of stresses induced in a belt with neat sketch and State
the different belt tension adjustment devices with neat sketch.
07
OR
Q.3 (a) (i) Give detailed classification of spring. List the materials for helical and leaf
Spring
03
(ii) What is nipping in a leaf spring? Discuss its role. Derive equation for
finding nipping in spring.
04
(b) Two parallel shafts connected by a crossed belt, are provided with pulleys 480
mm and 640 mm in diameters. The distance between the center line of the shaft
is 3 m. Find by how much the length of the belt should be changed if it is desired
to alter the direction of rotation of the driven shaft.
07
Q.4 (a) Sketch and explain various types of ends used for pressure vessels giving
practical applications of each.
07
(b) (i) Discuss bearing seals & lubrication of rolling contact bearings. 04
(ii) Discuss causes of failure of antifriction bearing. 03
OR
Q.4 (a) A seamless cylinder with storage capacity of 0.025 m
3
is made of plain carbon
steel 30C8 (Sut = 500 MPa) and it is used for storing a liquid at 15 MPa pressure.
The length of cylinder is twice its inner diameter. If the factor of safety is 2.5,
determine the dimensions of the cylinder.
07
(b) Give the difference between (i) Sliding contact bearing and Rolling contact
bearing. (ii) Hydrodynamic and Hydrostatic bearings
07
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1
Seat No.: ________ Enrolment No.___________
GUJARAT TECHNOLOGICAL UNIVERSITY
BE - SEMESTER ?V (OLD) EXAMINATION ? WINTER 2018
Subject Code:151905 Date: 07/12/2018
Subject Name: Machine Design - I
Time: 10:30 AM TO 01:00 PM Total Marks: 70
Instructions:
1. Attempt all questions.
2. Make suitable assumptions wherever necessary.
3. Figures to the right indicate full marks.
Q.1 (a) What do you mean by standardization? Explain role of preferred numbers in
standardization?
04
(b) What is Endurance Limit? Explain Design criteria with Solderberg?s line. 04
(c) Explain design of components for forging. 03
(d) Explain Manufacturing and assembly considerations in machine design 03
Q.2 (a) Define stress concentration factor. Explain methods for reducing stress
concentration with figure.
07
(b) A rotating bar made of steel 45C8 (Sut = 630 N/mm
2)
is subjected to a completely
reversed bending stress. The corrected endurance limit of the bar is 315 N/mm
2
.
Calculate the fatigue strength of the bar for a life of 90,000 cycles.
07
OR
(b) What is the importance of wear considerations in design? Explain the measures
to minimize the wear
07
Q.3 (a) Explain the following and state how can they be prevented? (i) Buckling of spring
(ii) Surge in springs
07
(b) Explain the different types of stresses induced in a belt with neat sketch and State
the different belt tension adjustment devices with neat sketch.
07
OR
Q.3 (a) (i) Give detailed classification of spring. List the materials for helical and leaf
Spring
03
(ii) What is nipping in a leaf spring? Discuss its role. Derive equation for
finding nipping in spring.
04
(b) Two parallel shafts connected by a crossed belt, are provided with pulleys 480
mm and 640 mm in diameters. The distance between the center line of the shaft
is 3 m. Find by how much the length of the belt should be changed if it is desired
to alter the direction of rotation of the driven shaft.
07
Q.4 (a) Sketch and explain various types of ends used for pressure vessels giving
practical applications of each.
07
(b) (i) Discuss bearing seals & lubrication of rolling contact bearings. 04
(ii) Discuss causes of failure of antifriction bearing. 03
OR
Q.4 (a) A seamless cylinder with storage capacity of 0.025 m
3
is made of plain carbon
steel 30C8 (Sut = 500 MPa) and it is used for storing a liquid at 15 MPa pressure.
The length of cylinder is twice its inner diameter. If the factor of safety is 2.5,
determine the dimensions of the cylinder.
07
(b) Give the difference between (i) Sliding contact bearing and Rolling contact
bearing. (ii) Hydrodynamic and Hydrostatic bearings
07
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2
Q.5 (a) List the factors affecting selection suitable clutch. What are the design
consideration points in the design of a friction clutch?
07
(b) Discuss briefly the considerations for selection of friction lining material. What
do you mean by a self-energizing brake and a self-locking brake?
07
OR
Q.5 (a) Why a positive clutch is used? Describe, with the help of neat sketches the
working of jaw or claw clutch.
07
(b) Compare the simple band brake and differential band brake. Explain the
importance of p-v product in break design
07
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This post was last modified on 20 February 2020