In the levers of first type, the mechanical advantage is __________ one.
Less than
Equal to
More than
None of these
Correct Answer :
C. More than
Related Questions
The process which improves the machinability of steels, but lowers the hardness and tensile strength is
Normalising
Full annealing
Process annealing
Spheroidising
Which is positive drive?
Flat belt drive
V-belt drive
Crossed belt drive
Timing belt
Buttress threads are usually found on
Screw cutting lathes
Feed mechanisms
Spindles of bench vices
Railway carriage couplings
The cam follower extensively used in aircraft engines is
Knife edge follower
Flat faced follower
Spherical faced follower
Roller follower
The effective stress in wire ropes during normal working is equal to the stress due to
Axial load plus stress due to bending
Acceleration/retardation of masses plus stress due to bending
Axial load plus stress due to acceleration/retardation
Bending plus stress due to acceleration/retardation
The taper on cotter varies from
1 in 24 to 1 in 20
1 in 15 to 1 in 10
1 in 32 to 1 in 24
1 in 48 to 1 in 24
A universal coupling is used to connect two shafts
Which are not in exact alignment
Which are perfectly aligned
Whose axes intersect at a small angle
Have lateral misalignment
A column of length l is fixed at both ends. The equivalent length of the column is
l/2
l/√2
l
2 l
The maximum efficiency of a square threaded screw is
(1 - sinφ)/ (1 + sinφ)
(1 + sinφ)/ (1 - sinφ)
(1 - sinφ)/ (1 + cosφ)
(1 + cosφ)/ (1 - sinφ)
For same pulley diameters, center distance, belt speed and belt and pulley materials,
Open belt drive transmits more power than crossed belt drive
Crossed belt drive transmits more power than open belt drive
Open and crossed belt drives transmit same power
Power transmission does not depend upon open and crossed types of constructions
The design of the pressure vessel is based on
Longitudinal stress
Hoop stress
Longitudinal and hoop stress
None of these
The piston pin bearings in heavy duty diesel engines are
Needle roller bearings
Tapered roller bearings
Spherical roller bearings
Cylindrical roller bearings
A machine part subjected to __________ is called a strut.
An axial compressive force
A tangential force
An axial tensile force
Any one of these
The design calculations for members subject to fluctuating loads with the same factor of safety, yield the most conservative estimates when using
Gerber relation
Soderberg relation
Goodman relation
None of these
The fatigue stress concentration factor is defined as
The ratio of endurance limit with stress concentration to the endurance limit without stress concentration
The ratio of endurance limit without stress concentration to the endurance limit with stress concentration
The product of the endurance limits with and without stress concentration
All of the above
When the bolt is very yielding as compared to the connected members, 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
The allowable static stress for steel gears is approximately __________ of the ultimate tensile stress.
One-fourth
One-third
One-half
Double
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
According to Indian standards, total numbers of tolerance grades are
8
12
18
20
Which of the following has threads at both ends?
Bolt
Tap bolt
Stud
None of these
In a multiple V-belt drive, when a single belt is damaged, it is preferable to change the complete set in order to
Reduce vibration
Reduce slip
Ensure uniform loading
Ensure proper alignment
The arms of the pulleys for flat belt drive have
Elliptical cross-section
Major axis in plane of rotation
Major axis twice the minor axis
All the three characteristics
The relation between the pitch of the chain (p) and pitch circle diameter of the sprocket (D) is given by (where T = Number of teeth on the sprocket)
p = D sin (90°/T)
p = D sin (120°/T)
p = D sin (180°/T)
p = D sin (360°/T)
In designing a sleeve coupling, length of the sleeve is taken as (where d = Diameter of the shaft)
d + 17 mm
2d + 13 mm
2d + 20 mm
3.5d
The velocity factor for precision metallic gears cut with high accuracy and operating at velocities upto 20 m/s is equal to
0.75/ (0.75 + √v)
3/ (3 + v)
4.5/ (4.5 + v)
6/ (6 + v)
The stretching in a belt can be controlled by __________ the stress in the belt.
Reducing
Increasing
Both A and B
None of these
In the levers of first type, the mechanical advantage is __________ one.
Less than
Equal to
More than
None of these
In a gear, having Involute teeth, the normal to the Involute is a tangent to the
Base circle
Pitch circle
Addendum circle
Dedendum circle
In block brakes, the ratio of shoe width to wheel diameter is taken between
0.1 and 0.25
0.25 and 0.50
0.50 and 0.75
0.75 and 1
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