Creep in belt drive is due to
Material of the pulley
Material of the belt
Larger size of the driver pulley
Uneven extensions and contractions due to varying tension
Correct Answer :
D. Uneven extensions and contractions due to varying tension
Related Questions
The angle of inclination of the plane, at which the body begins to move down the plane is called
Angle of friction
Angle of repose
Angle of projection
None of these
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)
Torsional vibrations are said to occur when the particles of a body moves
Perpendicular to its axis
Parallel to its axis
In a circle about its axis
None of these
Coriolis component is encountered in
Quick return mechanism of shaper
Four bar chain mechanism
Slider crank mechanism
Both (A) and (C) above
A system of masses rotating in different parallel planes is in dynamic balance if the
Resultant force is equal to zero
Resultant couple is equal to zero
Resultant force and resultant couple are both equal to zero
Resultant force is numerically equal to the resultant couple, but neither of them need necessarily be zero
The train value of a gear train is
Equal to velocity ratio of a gear train
Reciprocal of velocity ratio of a gear train
Always greater than unity
Always less than unity
The advantage of the piston valve over the slide valve is that in the former case
Wear is less
Power absorbed is less
Both wear and power absorbed are low
The pressure developed being high provides tight sealing
In a pantograph, all the pairs are
Turning pairs
Sliding pairs
Spherical pairs
Self-closed pairs
The tendency of a body to resist change from rest or motion is known as
Mass
Friction
Inertia
Resisting force
In a mechanism, usually one link is fixed. If the fixed link is changed in a kinematic chain, then relative motion of other links
Will remain same
Will change
Could change or remain unaltered depending on which link is fixed
Will not occur
A simple spring-mass vibrating system has a natural frequency of fn. If the spring stiffness is halved and the mass is doubled, then the natural frequency will become
fn/2
2 fn
4 fn
8 fn
The balancing weights are introduced in planes parallel to the plane of rotation of the disturbing mass. To obtain complete dynamic balance, the minimum number of balancing weights to be introduced in different planes is
1
2
3
4
Which of the following is a higher pair?
Belt and pulley
Turning pair
Screw pair
Sliding pair
The frictional torque transmitted in a truncated conical pivot bearing, considering uniform wear, is
(1/2). μ W cosec α (r₁ + r₂)
(2/3).μ W cosec α (r₁ + r₂)
(1/2). μ W cosec α [(r₁³ - r₂³)/(r₁² - r₂²)]
(2/3). μ W cosec α [(r₁³ - r₂³)/(r₁² - r₂²)]
A governor is said to be stable, if the
Radius of rotation of balls increases as the equilibrium speed decreases
Radius of rotation of balls decreases as the equilibrium speed decreases
Radius of rotation of balls increases as the equilibrium speed increases
Radius of rotation of balls decreases as the equilibrium speed increases
The mechanism forms a structure, when the number of degrees of freedom (n) is equal to
0
1
2
-1
In a cam drive with uniform velocity follower, the sharp corners of the displacement diagram are rounded off at the beginning and at the end of each stroke. This is done
Because of difficulty in manufacturing cam profile
Because of loose contact of follower with cam surface
In order to have acceleration in beginning and retardation at the end of stroke within the finite limits
Because the uniform velocity motion is a partial parabolic motion
The radius of a friction circle for a shaft rotating inside a bearing is (where r = Radius of shaft, and tan φ = Coefficient of friction between the shaft and bearing)
r sinφ
r cosφ
r tanφ
(r/2) cosφ
Which of the following mechanisms produces mathematically an exact straight line motion?
Grasshopper mechanism
Watt mechanism
Peaucellier's mechanism
Tchebicheff mechanism
In under damped vibrating system, if x₁ and x₂ are the successive values of the amplitude on the same side of the mean position, then the logarithmic decrement is equal to
x₁/x₂
log(x₁/x₂)
loge(x₁/x₂)
log(x₁.x₂)
The number of links in pantograph mechanism is equal to
2
3
4
5
The pressure angle of a cam is the angle between the direction of the follower motion and a normal to the
Pitch circle
Base circle
Pitch curve
Prime circle
For simple harmonic motion of the of follower, a cosine curve represents
Displacement diagram
Velocity diagram
Acceleration diagram
All of the above
Which of the following statements regarding laws governing the friction between dry surfaces are correct?
The friction force is dependent on the materials of the contact surfaces.
The friction force is directly proportional to the normal force.
The friction force is independent of me area of contact.
All of the above
The equation of motion for a single degree of freedom system with viscous damping is 4(dx²/dt²) + 9(dx/dt) + 16x. The damping ratio of the system is
9/8
9/82
9/16
9/128
Rectilinear motion of piston is converted into rotary by
Cross head
Slider crank
Connecting rod
Gudgeon pin
In locomotives, the ratio of the connecting rod length to me crank radius is kept very large in order to
Minimise the effect of primary forces
Minimise the effect of secondary forces
Have perfect balancing
To start the locomotive quickly
It is required to connect two parallel shafts, the distance between whose axes is small and variable. The shafts are coupled by
Universal joint
Knuckle joint
Oldham's coupling
Flexible coupling
The two links OA and OB are connected by a pin joint at O. If the link OA turns with angular velocity ω₁ rad/s in the clockwise direction and the link OB turns with angular velocity ω₂ rad/s in the anticlockwise direction, then the rubbing velocity at the pin joint O is (where r = Radius of the pin at O)
ω₁.ω₂.r
(ω₁ - ω₂) r
(ω₁ + ω₂) r
(ω₁ - ω₂) 2r
The size of cam depends upon
Base circle
Pitch circle
Prime circle
Pitch curve