In a partial journal bearing, the angle of contact of the bearing with the journal is
120°
180°
270°
360°
Correct Answer :
A. 120°
Related Questions
The permissible stress for carbon steel under static loading is generally taken as
2000-3000 kg/m²
3000-4000 kg/cm²
4000-4500 kg/cm²
7500-10,000 kg/cm²
A circular shaft can transmit a torque of 5 kN-m. If the torque is reduced to 4 kN-m, then the maximum value of bending moment that can be applied to the shaft is
1 kN-m
2 kN-m
3 kN-m
4 kN-m
Stress concentration factor is defined as the ratio of
Maximum stress to the endurance limit
Nominal stress to the endurance limit
Maximum stress to the nominal stress
Nominal stress to the maximum stress
Set screws are
Similar to small size tap bolts except that a greater variety of shapes of heads are available
Slotted for a screw driver and generally used with a nut
Used to prevent relative motion between parts
Similar to stud
In skew bevel gearing, the axes of shafts are
Intersecting and the teeth are curved
Non-intersecting and nonparallel and the teeth are curved
Non-intersecting and non-parallel and the teeth are straight
None of the above
The elasticity is the property of a material which enables it to
Regains its original shape after deformation when the external forces are removed
Draw into wires by the application of a tensile force
Resists fracture due to high impact loads
Retain deformation produced under load permanently
Rankine's theory of failure is applicable for following type of materials
Brittle
Ductile
Elastic
Plastic
The coefficient of friction in belt drive depends upon
Material of belt
Material of pulley
Materials of belt and pulley
Belt velocity
Multiple threads are used to secure
Low efficiency
High efficiency
High load lifting capacity
High mechanical advantage
The included angle for the British Association thread is
29°
55°
47.3°
60°
When two helical springs of equal lengths are arranged to form a cluster spring, then
Shear stress in each spring will be equal
Load taken by each spring will be half the total load
Only A is correct
Both A and B is correct
When a bolt is subjected to shock loading, the resilience of the bolt should be considered in order to prevent breakage at the
Thread
Middle
Shank
Head
Spring stiffness is
Ratio of coil diameter to wire diameter
Load required to produce unit deflection
Its capability of storing energy
Its ability to absorb shocks
Which of the following coupling is used to connect two shafts which have both lateral and angular misalignment?
Bushed pin type coupling
Universal coupling
Oldham coupling
All of these
When an open coiled helical compression spring is subjected to an axial load (W), the compression produced in the spring will be (where n = No. of active turns of the spring, and G = Modulus of rigidity for the spring material)
2WD3n/Gd⁴
4WD3n/Gd⁴
8WD3n/Gd⁴
16WD3n/Gd⁴
Which of the following statement is wrong?
The pitch of rivets is obtained by equating the tearing resistance of the plate to the shearing resistance of the rivets
The pitch of rivets should not be less than 2d, where d is the diameter of rivet hole
The maximum value of the pitch of rivets for a longitudinal joint of a boiler, as per I.B.R., is given by Pmax = C.t + 41.28 mm
According to I.B.R., the thickness of butt strap shall not be less than 5 mm
Which of the following statement is correct?
The stress concentration in static loading is more serious in ductile materials and less serious in brittle materials
The stress concentration in static loading is more serious in brittle materials and less serious in ductile materials
The toughness of a material increases when it is heated
The shear stress in a beam varies from zero at the neutral surface and maximum at the outer fibres
When the speed of belt increases,
The coefficient of friction between the belt and pulley decreases
The coefficient of friction between the belt and pulley increases
The power transmitted will decrease
The power transmitted will increase
A feather key is generally
Loose in shaft and tight in hub
Tight in shaft and loose in hub
Tight in both shaft and hub
Loose in both shaft and hub
The expansion joint is mostly used for pipes which carry steam at __________ pressures.
Low
High
Medium
None of these
A bolt of M 24 × 2 means that
The pitch of the thread is 24 mm and depth is 2 mm
Cross-sectional area of the threads is 24 mm²
The nominal diameter of bolt is 24 mm and pitch is 2 mm
The effective diameter of bolt is 24 mm and there are 2 threads per cm
If d is the normal diameter of a bolt in mm, then the initial tension in kg in a bolt used for making a fluid tight joint as for steam engine cover joint is calculated by the relation
124 d
138 d
151 d
168 d
When the shaft rotates in anticlockwise direction at slow speed in a bearing, it will
Have contact at the bottom most of the bearing
Move towards right of the bearing making no metal to metal contact
Move towards right of the bearing making the metal to metal contact
Move towards left of the bearing making metal to metal contact
The property of a bearing material which has the ability to accomodate shaft deflections and bearing inaccuracies by plastic deformation without excessive wear and heating, is known as
Bondability
Embeddability
Comformability
Fatigue strength
The taper on a rectangular sunk key is
1 in 16
1 in 32
1 in 48
1 in 100
The centrifugal tension in belts
Decreases the power transmitted
Increases the power transmitted
Increase the wrap angle
Increases the belt tension without increasing power transmission
The cracks in helical springs used in railway carriages usually start on the inner side of the coil because of the fact that
It is subjected to a higher cyclic loading than the outer side
It is subjected to a higher stress than the outer side
It is more stretched than the outer side during the manufacturing process
It has a lower curvature than the outer side
An alien bolt is
Self locking bolt
Same as stud
Provided with hexagonal depression in head
Used in high speed components
A taper key which fits half in the key way of the hub and half in the key way of shaft, is known as
Angular bevel gears
Mitre gears
Crown Bevel gears
Internal bevel gears
When an open coiled helical compression spring is subjected to an axial compressive load, the maximum shear stress induced in the wire is (where D = Mean diameter of the spring coil, d = Diameter of the spring wire, K = Wahl's stress factor, and W = Axial compressive load on the spring)
(WD/ πd3) × K
(2WD/ πd3) × K
(4WD/ πd3) × K
(8WD/ πd3) × K