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
Correct Answer :
C. The power transmitted will decrease
Related Questions
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
A leaf spring in automobiles is used
To apply forces
To measure forces
To absorb shocks
To store strain energy
The draw of cotter should not be more than
3 mm
6 mm
8 mm
12 mm
When spring index increases, the value of Wahl's stress factor
Increases linearly
Decreases linearly
Remains same
Increases exponentially
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
Oil in journal bearing should be applied at the point where load is
Nil or lightest
Maximum
Average
Any one of the above
Two helical springs of the same material and of equal circular crosssection, length and number of turns, but having radii 80 mm and 40 mm, kept concentrically (smaller radius spring within the larger radius spring), are compressed between two parallel planes with a load W. The inner spring will carry a load equal to
W/2
2W/3
W/9
8W/9
In a gear, having Involute teeth, the normal to the Involute is a tangent to the
Base circle
Pitch circle
Addendum circle
Dedendum circle
For steel, the ultimate strength in shear as compared to ultimate strength in tension is
1/2
1/3
1/4
2/3
When a beam of rectangular cross-section of width b and depth d, is subjected to a shear force F, the maximum shear stress induced will be
F/bh
3F/2bh
2F/bh
4F/bh
The resultant axial load on a bolt depends upon
External load applied
Initial tension due to tightening of the bolt
Relative elastic yielding of the bolt and the connected members
All of the above
The most important dimension in the design of a nut is
Pitch diameter
Inside diameter
Outside diameter
Height
The metal suitable for bearings subjected to heavy loads is
White metal
Silicon bronze
Monel metal
Phosphor bronze
In order to have a connecting rod equally strong in buckling about X-axis and Y-axis, the moment of inertia about X-axis should be __________ the moment of inertia about Y-axis.
Equal to
Twice
Three times
Four times
According to Indian standards, a bolt thread of 6 mm size of coarse pitch and with allowance on the threads and normal tolerance grade is designated as
M6
M8
M6 - 8d
M8 - 6d
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
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
For maximum power, the velocity of the belt will be
√(T/m)
√(T/2m)
√(T/3m)
None of these
In a flange coupling, the bolts are subjected to
Tensile stress
Compressive stress
Shear stress
None of these
Slenderness ratio is the ratio of
Effective length of column to least radius of gyration of the column
Width of column to depth of column
Maximum size of column to minimum size of column
Effective length of column to width of column
For a shaft diameter of 200 mm, the number of bolts in a marine flange coupling should be
8
6
4
10
The ratio of driving tensions for flat belts, neglecting centrifugal tension, is (where T₁, and T₂ = Tensions on the tight and slack sides of belt respectively, μ = Coefficient of friction, between the belt and pulley, and θ = Angle of contact)
T₁/T₂ = μθ
log (T₁/T₂) = μθ
T₁/T₂ =eμθ
T₁/T₂ = log μθ
When an open coiled helical compression spring is subjected to an axial compressive load, the stress induced in the wire is
Tensile stress
Compressive stress
Shear stress
Bending stress
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
The included angle in unified of American National threads is
60°
55°
47°
29°
The process extensively used for making bolts and nuts is
Hot piercing
Extrusion
Cold peening
Cold heading
When compared to the rod of the same diameter and material, a wire rope
Is less flexible
Has a much smaller load carrying capacity
Does not provide much warning before failure
Provides much greater time for remedial action before failure
Taper usually provided on cotter is
1 in 5
1 in 10
1 in 24
1 in 40
For a square key made of mild steel, the shear and crushing strength are related as
Shear strength is equal to crushing strength
Shear strength is greater than crushing strength
Shear strength is less than crushing strength
None of the above
Cast iron pipes are mainly used
For conveying steam
In water and sewage systems
In pressure lubrication systems on prime movers
All of the above