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4

Two heavy rotating masses are connected by shafts of lengths l₁, l₂ and l₃ and the corresponding diameters are d₁, d₂ and d₃. This system is reduced to a torsionally equivalent system having uniform diameter d = d₁ of the shaft. The equivalent length of the shaft is

A. (l₁ + l₂ + l₃)/3

B. l = l₁ + l₂.(d₁/d₂)³ + l₂.(d₁/d₃)³

C. l = l₁ + l₂.(d₁/d₂)⁴ + l₃.(d₁/d₃)⁴

D. l₁ + l₂ + l₃

Correct Answer :

C. l = l₁ + l₂.(d₁/d₂)⁴ + l₃.(d₁/d₃)⁴


Related Questions

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4

Which of the following mechanism is an approximate straight line motion mechanism?

A. Watt's mechanism

B. Grasshopper mechanism

C. Robert's mechanism

D. All of these

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4

A kinematic chain requires at least

A. 2 links and 3 turning pairs

B. 3 links and 4 turning pairs

C. 4 links and 4 turning pairs

D. 5 links and 4 turning pairs

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4

For two governors A and B, the lift of sleeve of governor A is more than that of governor B, for a given fractional change in speed. It indicates that

A. Governor A is more sensitive than governor B

B. Governor B is more sensitive than governor A

C. Both governors A and B are equally sensitive

D. None of the above

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4

The velocity of a flat-faced follower when it has contact with the flank of a circular arc cam, is given by

A. ωR cosθ

B. ω(R - r₁) cosθ

C. ω(R - r₁) sinθ

D. ωr₁ sinθ

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4

If D₁ and D₂ be the diameters of driver and driven pulleys, then belt speed is proportional to

A. D₁/D₂

B. D₂/D₁

C. D₁.D₂

D. D₁

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4

Which of the following disciplines provides study of inertia forces arising from the combined effect of the mass and the motion of the parts?

A. Theory of machines

B. Applied mechanics

C. Mechanisms

D. Kinetics

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4

The centre distance between two meshing involute gears is equal to

A. Sum of base circle radii/cosφ

B. Difference of base circle radii/ cosφ

C. Sum of pitch circle radii/ cosφ

D. Difference of pitch circle radii/ cosφ

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4

The Coriolis component of acceleration acts

A. Along the sliding surface

B. Perpendicular to the sliding surface

C. At 45° to the sliding surface

D. Parallel to the sliding surface

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4

Which of the following statement is wrong?

A. A round bar in a round hole form a turning pair

B. A square bar in a square hole form a sliding pair

C. A vertical shaft in a foot step bearing forms a successful constraint

D. All of the above

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4

In a multiple V-belt drive, when a single belt is damaged, it is preferable to change the complete set to

A. Reduce vibration

B. Reduce slip

C. Ensure uniform loading

D. Ensure proper alignment

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4

The approximate straight line mechanism is a

A. Four bar linkage

B. 6 bar linkage

C. 8 bar linkage

D. 3 bar linkage

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4

A slider moves at a velocity v on a link revolving at ω rad/s. The coriolis component of acceleration is

A. ωv

B. 2ωv

C. ω²v

D. 2ωv²

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4

Transmission angle is the angle between

A. Input link and coupler

B. Input link and fixed link

C. Output link and coupler

D. Output link and fixed link

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4

The motion between a pair which takes place in __________ is known as incompletely constrained motion.

A. One direction only

B. Two directions only

C. More than one direction

D. None of these

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4

For the brake to be self locking, the force P at C shown in the below figure, should

A. Be zero

B. Act in upward direction

C. Act in downward direction

D. None of these

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4

Which of the following mechanisms produces mathematically an exact straight line motion?

A. Grasshopper mechanism

B. Watt mechanism

C. Peaucellier's mechanism

D. Tchebicheff mechanism

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4

In a Hartnell governor, the stiffness of the spring is given by (where S1 and S2 = Spring forces exerted on the sleeve at max. and min. radii of rotation, and h = Compression of the spring)

A. (S₁ + S₂)/h

B. (S₁ - S₂)/h

C. (S₁ + S₂)/2h

D. (S₁ - S₂)/2h

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4

The Ackerman steering gear mechanism is preferred to the Davis steering gear mechanism, because

A. Whole of the mechanism in the Ackerman steering gear is on the back of the front wheels

B. The Ackerman steering gear consists of turning pairs

C. The Ackerman steering gear is most economical

D. Both (A) and (B)

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4

In a simple train of wheels, the velocity ratio __________ the intermediate wheels.

A. Depends upon

B. Is independent of

C. Either A or B

D. None of these

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4

The essential condition of placing the two masses, so that the system becomes dynamically equivalent, is (where l₁ and l₂ = Distance of two masses from the centre of gravity of the body, and kG = Radius of gyration of the body)

A. l₁ = kG

B. l₂ = kG

C. l₁l₂ = kG

D. l₁l₂ = kG²

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4

To transmit power from one rotating shaft to another whose axes are neither parallel nor intersecting, use?

A. Spur gear

B. Spiral gear

C. Bevel gear

D. Worm gear

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4

The acceleration of a particle at any instant has two components i.e. radial component and tangential component. These two components will be

A. Parallel to each other

B. Perpendicular to each other

C. Inclined at 45°

D. Opposite to each other

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4

In a steam engine, one method of obtaining the earlier cut-off with a simple slide valve is by increasing the angle of advance of the eccentric while the throw of the eccentric, steam lap and exhaust lap are kept constant. This method will

A. Cause withdrawing or throttling of steam

B. Reduce length of effective stroke of piston

C. Reduce maximum opening of port to steam

D. All of these

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4

The power of a Porter governor is equal to

A. [c²/(1 + 2c)] (m + M) g.h

B. [2c²/(1 + 2c)] (m + M) g.h

C. [3c²/(1 + 2c)] (m + M) g.h

D. [4c²/(1 + 2c)] (m + M) g.h

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4

The mechanism in which two are turning pairs and two are sliding pairs, is called a

A. Double slider crank chain

B. Elliptical trammel

C. Scotch yoke mechanism

D. All of these

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4

In a band and block brake, the ratio of tensions on tight side and slack side of the band is (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)

A. T₁/T₂ = μ. θ. n

B. T₁/T₂ = [(1 - μ tanθ)/(1 + μ tanθ)]n

C. T₁/T₂ = (μ θ)n

D. T₁/T₂ = [(1 + μ tanθ)/(1 - μ tanθ)]n

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4

In a rigid link OA, velocity of A w.r.t. O will be

A. Parallel to OA

B. Perpendicular to OA

C. At 45° to OA

D. Along AO

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4

Shaft revolving in a bearing is the following type of pair

A. Lower pair

B. Higher pair

C. Spherical pair

D. Cylindrical pair

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4

The secondary unbalanced force is __________ the primary unbalanced force.

A. One-half

B. Two-third

C. n times

D. 1/n times

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4

The ratio of the maximum displacement of the forced vibration to the deflection due to the static force, is known as

A. Damping factor

B. Damping coefficient

C. Logarithmic decrement

D. Magnification factor