Which of the following statement is wrong?
The V-belt may be operated in either direction with tight side of the belt at the top or bottom
The V-belt drive is used with large centre distance
The power transmitted by V-belts is less than flat belts for the same coefficient of friction, arc of contact and allowable tension in the belts
The ratio of driving tensions in V-belt drive is more than flat belt drives
Correct Answer :
B. The V-belt drive is used with large centre distance
Related Questions
Transverse fillet welded joints are designed for
Tensile strength
Compressive strength
Shear strength
Bending strength
In thrust bearings, the load acts
Along the axis of rotation
Parallel to the axis of rotation
Perpendicular to the axis of rotation
In any direction
According to I.B.R., the factor of safety of riveted joint should not be less than
1
2
3
4
A hot short metal is
Brittle when cold
Brittle when hot
Brittle under all conditions
Ductile at high temperature
The bearings of heavy series have capacity ________ over the medium series.
20 to 30%
10 to 20%
30 to 40%
40 to 50%
The bearings of medium series have capacity __________ over the light series.
10 to 20 %
20 to 30 %
30 to 40 %
40 to 50 %
In a flange coupling, the flanges are coupled together by means of
Bolts and nuts
Studs
Headless taper bolts
None of these
Castle nut is a locking device in which
One smaller nut is tightened over main nut and main nut tightened against smaller one by loosening, creating friction jamming
A slot is cut partly is middle of nut and then slot reduced by tightening a screw
A hard fibre or nylon cotter is recessed in the nut and becomes threaded as the nut is screwed on the bolt causing a tight grip
Through slots are made at top and a cotter pin is passed through these and a hole in the bolt, and cotter pin spitted and bent in reverse direction at other end
In helical gears, the distance parallel to the axis, between similar faces of adjacent teeth, is called
Normal pitch
Axial pitch
Diametral pitch
Module
The maximum normal stress theory is used for
Plastic materials
Brittle materials
Non-ferrous materials
Ductile materials
A fast and loose pulley drive is used when
Shafts are arranged parallel and rotate in the opposite directions
Shafts are arranged parallel and rotate in the same directions
Shafts are arranged at right angles and rotate in one definite direction
Driven shaft is to be started or stopped whenever desired without interfering with the driving shaft
A plate with an elliptical hole in the centre, with semi-major axis (A) perpendicular to the direction of loading and semi-minor axis (b) along the direction of loading, is subjected to a pull P. The maximum stress induced at the edge of the hole is equal to (where σ = Stress for a plate with no hole i.e. nominal stress)
σ [1 + (b/2a)]
σ [1 + (2a/b)]
σ [1 + (b/3a)]
σ [1 + (3a/b)]
In worm gears, the pressure angle is ________ the angle between two inclined faces in axial plane.
Half
Twice
Thrice
None of these
Oil in journal bearing should be applied at the point where load is
Nil or lightest
Maximum
Average
Any one of the above
The material generally used for aircraft components is
Mild steel
High speed steel
Stainless steel
Aluminium
When a hole of diameter d is punched in a metal of thickness 't', then the force required to punch a hole is equal to (where τu = Ultimate shear strength of the material of the plate)
d.t.τu
πd.t.τu
π/4 × d².τu
π/4 × d² × t.τu
According to Indian standards, the diameter of rivet hole is made larger than the basic size of rivet by
0.5 mm upto rivet diameter of 24 mm
1 mm for rivet diameter from 27 mm to 36 mm
2 mm for rivet diameter from 39 mm to 48 mm
All of the above
Which of the following spring is used in mechanical wrist watch?
Helical compression spring
Spiral spring
Torsion spring
Belleville spring
If an application calls for stresses on screw threads in one direction only, then the following type of thread would be best suited
Square
Acme
Buttress
BSW
The creep in the belt is due to
Effect of temperature on belt
Material of belt
Unequal extensions in the belt due to tight and slack side tensions
Stresses beyond elastic limit of belt material
A coupling used to connect two perfectly aligned shafts, is
Muff coupling
Compression coupling
Flange coupling
All of these
The helix angle for single helical gears ranges from
10° to 15°
15° to 20°
20° to 35°
35° to 50°
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 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
The value of stress concentration factor depends upon
Material and geometry of the part
Geometry of the part
Material of the part
None of these
The resilience of a bolt may be increased by
Increasing its shank diameter
Increasing its length
Decreasing its shank diameter
Decreasing its length
Two rigid plates are clamped by means of bolt and nut with an initial force F. After tightening, a separating force P (P < F) is applied to the lower plate, which in turn acts on the nut. The tension in the both after this is
F + P
F P
P
F
The design of the pressure vessel is based on
Longitudinal stress
Hoop stress
Longitudinal and hoop stress
None of these
If T₁ and T₂ are the tensions on the tight and slack sides of the belt respectively, and Tc is the centrifugal tension, then initial tension in the belt is equal to
T₁ - T₂ + Tc
T₁ + T₂ + Tc
(T₁ - T₂ + Tc)/2
(T₁ + T₂ + Tc)/2
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