The coefficient of friction in belt drive depends upon
Material of belt
Material of pulley
Materials of belt and pulley
Belt velocity
Correct Answer :
C. Materials of belt and pulley
Related Questions
Taper usually provided on cotter is
1 in 5
1 in 10
1 in 24
1 in 40
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
A spring is used to
Measure forces
Apply forces
Store energy
All 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
In case of pressure vessels having open ends, the fluid pressure induces
Longitudinal stress
Circumferential stress
Shear stress
None of these
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
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
The included angle between the sides of V-belt is
40°
45°
38°
60°
In designing a connecting rod, it is considered like __________ for buckling about Y-axis.
Both ends hinged
Both ends fixed
One end fixed and the other end hinged
One end fixed and the other end free
The smallest diameter of an external or internal screw thread is known as
Minor diameter
Major diameter
Pitch diameter
None of these
The stretching in a belt can be controlled by __________ the stress in the belt.
Reducing
Increasing
Both A and B
None of these
The most important dimension in the design of a nut is
Pitch diameter
Inside diameter
Outside diameter
Height
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
The expression 0.175 - 0.841/T is the Lewis form factor for
14 ½° composite and full depth involute system
20° full depth involute system
20° stub system
None of the above
The shearing stresses in the inner face as compared to outer face of the wire in a heavy close coiled spring is
Larger
Smaller
Equal
Larger/smaller depending on diameter of spring coil
In order to determine the stresses in a thin cylinder due to an internal pressure, it is assumed that
The effect of curvature of the cylinder wall is neglected
The tensile stresses are uniformly distributed over the section of the walls
The effect of the restraining action of the heads at the end of the pressure vessel is neglected
All of the above
The steel pulleys are __________ in weight than cast iron pulleys of the same capacity.
Heavier
Lighter
Moderate
None of these
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
Which of the following statement is correct?
A parallel sunk key is a taperless key
A parallel sunk key may be rectangular or square in cross-section
A flat saddle key is a taper key which fits in a key way of the hub and is flat on the shaft
All of the above
In case of V-belt drive
The belt should touch the bottom of groove in the pulley
The belt should not touch the bottom of groove in the pulley
The belt should not touch the sides of groove in the pulley
None of the above
For unequal width of butt straps, the thicknesses of butt straps are
0.75 t for narrow strap on the inside and 0.625 t for wide strap on the outside
0.75 t for wide strap on the inside and 0.625 t for narrow strap on the outside
0.75 t for both the straps on the inside and outside
0.625 t for both the straps on the inside and outside
Crushing resistance required to crush the rivet per pitch length is
p.d.σc
p.t.σc
n.d.t.σc
(p - d) t.σc
The modulus of elasticity for mild steel is approximately equal to
80 kN/mm²
100 kN/mm²
110 kN/mm²
210 kN/mm²
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
The ratio of endurance limit in shear to the endurance limit in flexure is
0.33
0.4
0.5
0.55
The rolling contact bearings are known as
Thick lubricated bearings
Plastic bearings
Antifriction bearings
Thin lubricated bearings
A crankshaft is a __________ shaft.
Transmission
Machine
Machine frame
None of these
The pipe joint mostly used for pipes carrying water at low pressures is
Socket joint
Nipple joint
Union joint
Spigot and socket joint
Which of the following statement is correct?
The distance from a point on one thread to the corresponding point on the next thread is called pitch
The distance which a screw thread advances axially in one rotation of the nut is called lead
In single start threads, lead is equal to pitch
All of the above
For maximum power, the velocity of the belt will be
√(T/m)
√(T/2m)
√(T/3m)
None of these