Download PDF
Free download in PDF Machine Design Short Questions & Answers for competitive exams. These short objective type questions with answers are very important for Board exams as well as competitive exams. These short solved questions or quizzes are provided by Gkseries.
41
The sleeve or muff coupling is designed as a
[A]
dun cylinder
[B]
thick cylinder
[C]
solid shaft
[D]
hollow shaft
42
Screws used for power transmission should have
[A]
Low efficiency
[B]
high efficiency
[C]
very fine threads
[D]
strong teeth
43
A sliding bearing which operates without any lubricant present, is called
[A]
zero film bearing
[B]
boundary lubricated bearing
[C]
hydrodynamic lubricated bearing
[D]
hydrostatic lubricated bearing
Answer: zero film bearing
44
The difference between the tooth space and the tooth thickness as measured on the pitch circle, is called
[A]
backlash
[B]
face width
[C]
working depth
[D]
clearance
45
A locking device extensively used in marine type connecting rod ends is a
[A]
ring nut
[B]
sawn nut
[C]
jam nut
[D]
castle nut
46
When a nut is tightened by placing a washer below it, the bolt will be subjected to
[A]
tensile stress
[B]
compressive stress
[C]
shear stress
[D]
none of these
47
When two non-intersecting and non-coplaner shafts are connected by gears, the arrangement is known as
[A]
spiral gearing
[B]
bevel gearing
[C]
spur gearing
[D]
helical gearing
48
The maximum normal stress theory is used for
[A]
brittle materials
[B]
plastic materials
[C]
ductile materials
[D]
non-ferrous materials
Answer: brittle materials
49
The rolling contact bearings as compared to sliding contact bearings have
[A]
small overall dimensions
[B]
accuracy of shaft alignment
[C]
low starting and low running friction except at very high speeds
[D]
all of the above
50
When the bearing is subjected to large fluctuations of load and heavy impacts, the bearing characteristic number should be __________ the bearing modulus.
[A]
5 times
[B]
10 times
[C]
15 times
[D]
20 times
51
Which of the following screw thread is used for power transmission in one direction only.
[A]
Acme threads
[B]
Square threads
[C]
Buttress threads
[D]
Multiple threads
52
A screw will be self locking, if
[A]
friction angle is less than helix angle
[B]
friction angle is more than helix angle
[C]
friction angle is equal to helix angle
[D]
efficiency of screw is 100%
Answer: friction angle is more than helix angle
53
The expression 0.175 – 0.841/T is the Lewis form factor for
[A]
2°composite and full depth involute system
[B]
20° full depth involute system
[C]
20° stub system
[D]
none of the above
54
The longitudinal stress is __________ of the circumferential stress.
[A]
one-half
[B]
two-third
[C]
three-fourth
[D]
double
55
A shaft is subjected to a maximum bending stress of 80 N/mm2 and maximum shearing stress equal to 30 N/mm2 at a particular section. If the yield point in tension of the material is 280 N/mm2 and the maximum shear stress theory of failure is used, then the factor of safety obtained will be
[A]
2.5
[B]
2.8
[C]
3.0
[D]
3.5
56
When spring index increases, the value of Wahl’s stress factor
[A]
increases linearly
[B]
decreases linearly
[C]
remains same
[D]
increases exponentially
Answer: increases exponentially
57
Idler pulley is used for
[A]
increasing velocity ratio
[B]
for applying tension
[C]
changing the direction of motion of belt
[D]
all of these
Answer: for applying tension
58
In worm gears, the angle between the tangent to the pitch helix and an element of the cylinder, is known as
[A]
helix angle
[B]
pressure angle
[C]
pitch lead angle
[D]
none of these
59
The cross-section of the arm of a bell crank lever is
[A]
I-section
[B]
elliptical
[C]
rectangular
[D]
any one of these
60
In designing a sleeve coupling, length of the sleeve is taken as (where d = Diameter of the shaft)
[A]
3.5 d
[B]
2 d + 20 mm
[C]
d + 17 mm
[D]
2 d + 13 mm
Take Mock Tests