The application of third type levers is found in
Handle of a hand pump
Hand wheel of a punching press
Lever of a loaded safety valve
A pair of tongs
Correct Answer :
D. A pair of tongs
Related Questions
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
An alien bolt is
Self locking bolt
Same as stud
Provided with hexagonal depression in head
Used in high speed components
In nitrated parts, the origins of the fatigue cracks will occur at
Surface
Just below the surface
Within the core
None of the above
Basic shaft is one
Whose upper deviation is zero
Whose lower deviation is zero
Whose lower as well as upper deviations are zero
Does not exist
In helical gears, the right hand helixes on one gear will mesh __________ helixes on the other gear.
Right hand
Left hand
Both A and B
None of these
The process extensively used for making bolts and nuts is
Hot piercing
Extrusion
Cold peening
Cold heading
In levers, leverage is the ratio of
Load lifted to the effort applied
Mechanical advantage to the velocity ratio
Load arm to the effort arm
Effort arm to the load arm
The initial tension (in newtons) in a bolt used for making a fluid tight joint like steam engine cover joints, is calculated by the relation (where d = Nominal diameter of bolt in mm)
1420 d
1680 d
2080 d
2840 d
A shaft is subjected to fluctuating loads for which the normal torque (T) and bending moment (M) are 1000 N-m and 500 N-m respectively. If the combined shock and fatigue factor for bending is 1.5 and combined shock and fatigue factor for torsion is 2, then the equivalent twisting moment for the shaft is
2000 N-m
2050 N-m
2100 N-m
2136 N-m
The condition for maximum power transmission is that the maximum tension in the flat belt should be equal to
3 Pc
Pc
Pc/3
2 Pc Where, Pc = tension in belt due to centrifugal force
The following type of nut is used with alien bolt
Hexagonal nut
Slotted nut
Castle nut
Any one of the above
The material used for brake lining should have __________ coefficient of friction.
Low
High
Moderate
None of these
Resistance to fatigue of a material is measured by
Young's modulus
Coefficient of elasticity
Elastic limit
Endurance limit
In a band and block brake, the ratio of tensions on the tight and slack sides of band is given by (where μ = Coefficient of friction between the blocks and the drum, θ = Semi-angle of each block subtending at the centre of drum, and n = Number of blocks)
T₁/T₂ = μθ × n
T₁/T₂ = (μθ)n
T₁/T₂ = [(1 - μ tanθ)/ (1 + μ tanθ)]n
T₁/T₂ = [(1 + μ tanθ)/ (1 - μ tanθ)]n
A transmission shaft includes
Over head shaft
Counter shaft
Line shaft
All of these
The product of the diametral pitch and circular pitch is equal to
1
1/π
π
π × number of teeth
Which of the following statement is wrong for a connecting rod?
The connecting rod will be equally strong in buckling about X-axis and Y-axis, if Ixx = 4 Iyy
If Ixx > 4 Iyy, the buckling will occur about Y-axis
If Ixx < 4 Iyy, the buckling will occur about X-axis
The most suitable section for the connecting rod is T-section
A self locking screw has
Fine threads
Course threads
Coefficient of friction is greater than tangent of load angle
Hole for inserting split pin
The expansion joint is mostly used for pipes which carry steam at __________ pressures.
Low
High
Medium
None of these
The function of a washer is to
Provide cushioning effect
Provide bearing area
Absorb shocks and vibrations
Provide smooth surface in place of rough surface
When screw threads are to be used in a situation where power is being transmitted in one direction only, then the screw threads suitable for this will be
Knuckle threads
Square threads
Acme threads
Buttress threads
Which of the following statement is correct?
The cold rolled shafting is stronger than hot rolled shafting
The hot rolled shafting is stronger than cold rolled shafting
The cold rolled and hot rolled shaftings are equally strong
The shafts are not made by rolling process
When the belt is transmitting maximum power, the belt speed should be
√(Pmax / 2m)
√(Pmax / 3m)
√(Pmax / m)
√(3m /Pmax) Where m = mass of belt per metre (kg/m) Pmax = maximum permissible tension in belt (N)
Basic hole is one
Whose upper deviation is zero
Whose lower deviation is zero
Whose lower as well as upper deviations are zero
Does not exist
A bolt is designed on the basis of __________ with a large factor of safety.
Direct tensile stress
Direct compressive stress
Direct bending stress
Direct shear stress
A crankshaft is a __________ shaft.
Transmission
Machine
Machine frame
None of these
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 temperature at which the new grains are formed in the metal is known as
Lower critical temperature
Upper critical temperature
Recrystallisation temperature
None of these
The connecting rod bolts are tightened up so that tightening stress
Is just sufficient to hold parts together
Approaches yield point
Is 50% of yield point
Is about yield point divided by safety factor
A spring is used to
Measure forces
Apply forces
Store energy
All of these