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4

If the number of links in a mechanism is equal to l, then the numbers of possible inversions are equal to

A. l - 2

B. l - 1

C. l

D. l + 1

Correct Answer :

C. l


Related Questions

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4

Cross head and guides form a

A. Lower pair

B. Higher pair

C. Turning pair

D. Sliding pair

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4

Minimum number of teeth for involute rack and pinion arrangement for pressure angle of 20° is

A. 18

B. 20

C. 30

D. 34

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4

A shaft has two heavy rotors mounted on it. The transverse natural frequencies, considering each of the rotor separately, are 100 Hz and 200 Hz respectively. The lowest critical speed is

A. 5,367 r.p.m.

B. 6,000 r.p.m.

C. 9,360 r.p.m.

D. 12,000 r.p.m.

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4

The frictional torque transmitted in a flat collar bearing, considering uniform pressure, is (where r₁ and r₂ = External and internal radii of collar respectively)

A. (1/2). μ W (r₁ + r₂)

B. (2/3). μ W (r₁ + r₂)

C. (1/2). μ W [(r₁³ - r₂³)/(r₁² - r₂²)]

D. (2/3). μ W [(r₁³ - r₂³)/(r₁² - r₂²)]

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4

The train value of a gear train is

A. Equal to velocity ratio of a gear train

B. Reciprocal of velocity ratio of a gear train

C. Always greater than unity

D. Always less than unity

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4

The included angle for the V-belt is usually

A. 10° to 20°

B. 20° to 30°

C. 30° to 40°

D. 60° to 80°

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4

The main disadvantage of the sliding pair is that it is

A. Bulky

B. Wears rapidly

C. Difficult to manufacture

D. Both (A) and (B) above

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4

In under damped vibrating system, the amplitude of vibration

A. Decreases linearly with time

B. Increases linearly with time

C. Decreases exponentially with time

D. Increases exponentially with time

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4

A body is said to be under forced vibrations, when

A. There is a reduction in amplitude after every cycle of vibration

B. No external force acts on a body, after giving it an initial displacement

C. A body vibrates under the influence of external force

D. None of the above

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4

When two links are connected by a pin joint, their instantaneous centre lies

A. On their point of contact

B. At the centre of curvature

C. At the centre of circle

D. At the pin joint

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4

The direction of Coriolis component of acceleration is the direction

A. Of relative velocity vector for the two coincident points rotated by 90° in the direction of the angular velocity of the rotation of the link

B. Along the centripetal acceleration

C. Along tangential acceleration

D. Along perpendicular to angular velocity

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4

In multi V-belt transmission, if one of the belt is broken, we have to change the

A. Broken belt

B. Broken belt and its adjacent belts

C. All the belts

D. There is no need of changing any one as remaining belts can take care of transmission of load

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4

In order to double the period of a simple pendulum, the length of the string should be

A. Halved

B. Doubled

C. Quadrupled

D. None of these

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4

Module of a gear is

A. D/T

B. T/D

C. 2D/T

D. 2T/D

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4

A friction circle is a circle drawn when a journal rotates in a bearing. Its radius depends upon the coefficient of friction and the

A. Magnitude of the forces on journal

B. Angular velocity of journal

C. Clearance between journal and bearing

D. Radius of journal

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4

The centre of gravity of a coupler link in a four bar mechanism will experience

A. No acceleration

B. Only linear acceleration

C. Only angular acceleration

D. Both linear and angular acceleration

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4

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)

A. ω √(x² - r²)

B. ω √(r² - x²)

C. ω² √(x² - r²)

D. ω² √(r² - x²)

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4

Which of the following is a pendulum type governor?

A. Watt governor

B. Porter governor

C. Hartnell governor

D. None of these

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4

In the two rotor system as shown in the below figure (I₁ < I₂), a node of vibration is situated

A. Between I₁, and I₂ but nearer I₁

B. Between I₁, and I₂ but nearer to I₂

C. Exactly in the middle of the shaft

D. Nearer to I₁ but outside

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4

In the below figure, PC is the connecting rod and OC is the crank making an angle θ with the line of stroke PO and rotates with uniform angular velocity at ω rad/s. The Klien's acceleration diagram for determining the acceleration of the piston P is shown by quadrilateral CQNO, the acceleration of the piston is _________ when the crank OC and connecting rod PC are at right angles to each other.

A. Infinity

B. Zero

C. Any +ve value

D. Any -ve value

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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

Typewriter constitutes

A. Machine

B. Structure

C. Mechanism

D. Inversion

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A Porter governor is a

A. Pendulum type governor

B. Dead weight governor

C. Spring loaded governor

D. Inertia governor

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4

In a vibrating system, if the actual damping coefficient is 40 N/m/s and critical damping coefficient is 420 N/m/s, then logarithmic decrement is equal to

A. 0.2

B. 0.4

C. 0.6

D. 0.8

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4

The danger of breakage and vibration is maximum

A. Below the critical speed

B. Near the critical speed

C. Above the critical speed

D. None of these

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4

The secondary unbalanced force is maximum when the angle of inclination of the crank with the line of stroke is

A. 0° and 90°

B. 180° and 360°

C. Both (A) and (B)

D. None of these

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4

The size of a gear is usually specified by

A. Pressure angle

B. Circular pitch

C. Diametral pitch

D. Pitch circle diameter

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4

Kinematic pairs are those which have

A. Two elements held together mechanically

B. Two elements having relative motion

C. Two elements having Coriolis component

D. Minimum of two instantaneous centres

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4

Whitworth quick return mechanism is obtained by inversion of

A. Slider crank mechanism

B. Kinematic chain

C. Five link mechanism

D. Roller cam mechanism

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A rigid body possesses ________degrees of freedom

A. One

B. Two

C. Four

D. Six