In V-belt drive, belt touches
At bottom
At sides only
Both at bottom and sides
Could touch anywhere
Correct Answer :
B. At sides only
Related Questions
At low temperatures (say 75°C) the notched bar impact value of steel
Increases markedly
Decreases markedly
Remain same
Depends on heat treatment carried out
The notch sensitivity q is expressed in terms of fatigue stress concentration factor Kf and theoretical stress concentration factor Kt as
(Kf + 1)/ (Kt + 1)
(Kf - 1)/ (Kt - 1)
(Kt + 1)/ (Kf + 1)
(Kt - 1)/ (Kf - 1)
Aircraft body is usually fabricated by
Welding
Pre-casting
Riveting
Casting
The dedendum circle diameter is equal to (where φ = Pressure angle)
Pitch circle diameter × cosφ
Addendum circle diameter × cosφ
Clearance circle diameter × cosφ
Pitch circle diameter × sinφ
For a bevel gear having the pitch angle θ, the ratio of formative number of teeth (TE) to actual number of teeth (T) is
1/sinθ
1/cosθ
1/tanθ
sinθ cosθ
The ball bearings are, usually, made from
Low carbon steel
High carbon steel
Medium carbon steel
High speed steel
The deflection of a cantilever beam under load W is 8. If its width is halved, then the deflection under load W will be
2/8
8/2
4/8
8/4
According to Indian standard specifications, 100 H6/g5 means that the
Basic size is 100 mm
Actual size is 100 mm
Difference between the actual size and basic size is 100 mm
None of the above
The resistance to fatigue of a material is measured by
Elastic limit
Ultimate tensile strength
Young's modulus
Endurance limit
Which is positive drive?
Flat belt drive
V-belt drive
Crossed belt drive
Timing belt
In a boundary lubricated bearing, there is a __________ of lubricant between the journal and the bearing.
Thick film
Thin film
Either A or B
None of these
In order to permit the thermal expansion/contraction of tubing, it should be
Crimped
Honed
Flared
Bent
While designing a screw in a screw jack against buckling failure, the end conditions for the screw are taken as
Both the ends fixed
Both the ends hinged
One end fixed and the other end hinged
One end fixed and the other end free
The coefficient of friction in belt drive depends upon
Material of belt
Material of pulley
Materials of belt and pulley
Belt velocity
According to Indian standards, total numbers of tolerance grades are
8
12
18
20
Allen bolts are
Self locking bolts
Designed for shock load
Used in aircraft application
Provided with hexagonal depression in head
In a steam engine, the piston rod is usually connected to the crosshead by means of a
Knuckle joint
Cotter joint
Oldham coupling
Universal joint
Which process will increase the fatigue duration of parts?
Finishing and polishing
Shotpeening
De-carburisation
Electroplating
For hardening alloy steels and high speed steels, they are heated to
1100 to 1300°C
1300 to 1500°C
500 to 600°C
700 to 900°C
When the length of the journal is equal to the diameter of the journal, then the bearing is said to be a
Short bearing
Long bearing
Medium bearing
Square bearing
Guest's theory of failure is applicable for following type of materials
Brittle
Ductile
Elastic
Plastic
The ratio of endurance limit in shear to the endurance limit in flexure is
0.33
0.4
0.5
0.55
The steel pulleys are __________ in weight than cast iron pulleys of the same capacity.
Heavier
Lighter
Moderate
None of these
The crest diameter of a screw thread is same as
Major diameter
Minor diameter
Pitch diameter
Core diameter
Stress concentration is caused due to
Variation in properties of material from point to point in a member
Pitting at points or areas at which loads on a member are applied
Abrupt change of section
All of the above
In oilness bearings
The oil film pressure is generated only by the rotation of the journal
The oil film is maintained by supplying oil under pressure
Do not require external supply of lubricant
Grease required to be applied after some intervals
If p = bearing pressure on projected bearing area, z = absolute viscosity of lubricant, and N = speed of journal, then the bearing characteristic number is given by
ZN/p
p/ZN
Z/pN
N/Zp
In a multiple V-belt drive, if one of the belts break, then
Only the broken belt is replaced
The entire set of belts is replaced
The broken belt and the belt on either side of it, is replaced
The broken belt need not to be replaced
An open belt drive is used when
Shafts are arranged at right angles and rotate in one definite direction
Shafts are arranged parallel and rotate in the opposite directions
Shafts are arranged parallel and rotate in the same directions
Driven shaft is to be started or stopped whenever desired without interfering with the driving shaft
When the connected members are very yielding (soft gasket) as compared to the bolt, then the resultant load on the bolt will be equal to the
Initial tension
External load applied
Sum of the initial tension and external load applied
Initial tension or external load, whichever is greater