The frictional torque transmitted in a flat pivot bearing, considering uniform wear, is (where μ = Coefficient of friction, W = Load over the bearing, and R = Radius of bearing surface)
(1/2) μ W R
(2/3) μ W R
(3/4) μ W R
μ W R
Correct Answer :
A. (1/2) μ W R
Related Questions
The tractive force in a locomotive with two cylinders is given by (where c = Fraction of reciprocating parts per cylinder, m = Mass of reciprocating parts, ω = Angular speed of crank, r = Radius of crank, and θ = Angle of inclination of crank to the line of stroke)
m.ω².r cosθ
c.m.ω².r sinθ
(1 - c).m.ω².r (cosθ - sinθ)
m.ω².r (cosθ - sinθ)
The pressure angle of a cam depends upon
Offset between centre lines of cam and follower
Lift of follower
Angle of ascent
All of the above
Angle of descent of cam is defined as the angle
During which the follower returns to its initial position
Of rotation of the cam for a definite displacement of the follower
Through which the cam rotates during the period in which the follower remains in the highest position
Moved by the cam from the instant the follower begins to rise, till it reaches its highest position
In order to give a complete secondary balance of a multi-cylinder inline engine,
The algebraic sum of the secondary forces must be equal to zero
The algebraic sum of the couples about any point in the plane of the secondary forces must be equal to zero
Both (A) and (B)
None of these
The relation between number of pairs (p) forming a kinematic chain and the number of links (l) is
l = 2p - 2
l = 2p - 3
l = 2p - 4
l = 2p - 5
In a kinematic chain, a quaternary joint is equivalent to
One binary joint
Two binary joints
Three binary joints
Four binary joints
The frequency of oscillation of a torsional pendulum is
2πk/r. √(g/l)
r/2πk. √(l/g)
2πr/k. √(g/l)
r/2πk. √(g/l)
For fluctuating loads, well suited bearing is
Ball bearing
Roller bearing
Needle roller bearing
Thrust bearing
The velocity of a particle moving with simple harmonic motion, at any instant is given by (where ω = Displacement of the particle from mean position)
ω √(x² - r²)
ω √(r² - x²)
ω² √(x² - r²)
ω² √(r² - x²)
Two systems shall be dynamically equivalent when
The mass of two are same
C.G. of two coincides
M.I. of two about an axis through e.g. is equal
All of the above
In elliptical trammels
All four pairs are turning
Three pairs turning and one pair sliding
Two pairs turning and two pairs sliding
One pair turning and three pairs sliding
The maximum or minimum value of the swaying couple is
± c.m.ω².r
± a (1 - c) m.ω².r
± (a/√2) (1 - c) m.ω².r
± 2a (1 - c) m.ω².r
In full depth involute system, the smallest number of teeth in a pinion which meshes with rack without interference is
12
16
25
32
When a ship travels in a sea, which of the effect is more dangerous
Steering
Pitching
Rolling
All of the above
The critical speed of a shaft depends upon its
Mass
Stiffness
Mass and stiffness
Stiffness and eccentricity
If the controlling force line for a spring controlled governor when produced intersects the Y-axis at the origin, then the governor is said to be
Stable
Unstable
Isochronous
None of these
There are six gears A, B, C, D, E and F in a compound train. The numbers of teeth in the gears are 20, 60, 30, 80, 25 and 75 respectively. The ratio of angular speeds of the driven (F) to the driver (A) of the drive is
1/24
1/8
4/15
12
A body will begin to move down an inclined plane, if the angle of inclination of the plane is ________ the angle of friction.
Equal to
Less than
Greater than
None of these
When the primary direct crank of a reciprocating engine makes an angle of θ with the line of stroke, then the secondary direct crank will make an angle of _________ with the line of stroke.
θ/2
θ
2θ
4θ
For a kinematic chain to be considered as mechanism
Two links should be fixed
One link should be fixed
None of the links should be fixed
There is no such criterion
In the two rotor system as shown in the below figure (I₁ < I₂), a node of vibration is situated 
Between I₁, and I₂ but nearer I₁
Between I₁, and I₂ but nearer to I₂
Exactly in the middle of the shaft
Nearer to I₁ but outside
The number of links in pantograph mechanism is equal to
2
3
4
5
Which of the following statement is wrong?
A round bar in a round hole form a turning pair
A square bar in a square hole form a sliding pair
A vertical shaft in a foot step bearing forms a successful constraint
All of the above
________ is an inversion of Double slider crank chain.
Coupling rod of a locomotive
Scotch yoke mechanism
Hand pump
Reciprocating engine
The unbalanced force due to revolving masses
Varies in magnitude but constant in direction
Varies in direction but constant in magnitude
Varies in magnitude and direction both
Constant in magnitude and direction both
In steady state forced vibrations, the amplitude of vibrations at resonance is __________ damping coefficient.
Equal to
Directly proportional to
Inversely proportional to
Independent of
When the crank is at the inner dead centre, in a reciprocating steam engine, then the velocity of the piston will be
Minimum
Zero
Maximum
None of these
The Coriolis component of acceleration acts
Along the sliding surface
Perpendicular to the sliding surface
At 45° to the sliding surface
Parallel to the sliding surface
For the brake to be self locking, the force P at C shown in the below figure, should 
Be zero
Act in upward direction
Act in downward direction
None of these
In a circular arc cam with roller follower, the acceleration in any position of the lift will depend only upon
Total lift, total angle of lift, minimum radius of cam and cam speed
Radius of circular arc, cam speed, location of centre of circular arc and roller diameter
Mass of cam follower linkage, spring stiffness and cam speed
Total lift, centre of gravity of the cam and cam speed