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4

In order to balance the reciprocating masses,

A. Primary forces and couples must be balanced

B. Secondary forces and couples must be balanced

C. Both (A) and (B)

D. None of these

Correct Answer :

C. Both (A) and (B)


Related Questions

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If the pressure angle is __________, a reciprocating follower will jam in its bearings.

A. Small

B. Too small

C. Large

D. Too large

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4

Throw of a cam is the maximum distance of the follower from

A. Base circle

B. Pitch circle

C. Root circle

D. Prime circle

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4

The frictional torque transmitted in a conical pivot bearing with assumption of uniform pressure is __________ as compared to uniform wear.

A. Less

B. More

C. Same

D. None of these

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4

In a shaper mechanism, the Coriolis component of acceleration will

A. Not exist

B. Exist

C. Depend on position of crank

D. None of the above

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4

In a single slider crank chain

A. Each of the four pairs is a turning pair

B. One is a turning pair and three are sliding pairs

C. Two are turning pairs and two are sliding pairs

D. Three are turning pairs and one is a sliding pair

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4

A circle passing through the pitch point with its center at the center of cam axis is known as

A. Pitch circle

B. Base circle

C. Prime circle

D. Outer circle

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4

The relation l = (2/3).(j + 2) apply only to kinematic chains in which lower pairs are used. This may be used to kinematic chains in which higher pairs are used, but each higher pair may be taken as equivalent to

A. One lower pair and two additional links

B. Two lower pairs and one additional link

C. Two lower pairs and two additional links

D. Any one of these

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4

For high speed engines, the cam follower should move with

A. Uniform velocity

B. Simple harmonic motion

C. Uniform acceleration and retardation

D. Cycloidal motion

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4

A disturbing mass m₁ attached to the rotating shaft may be balanced by a single mass m₂ attached in the same plane of rotation as that of m₁, such that (where r₁ and r₂ are the radii of rotation of m₁ and m₂ respectively)

A. m₁r₂ = m₂r₁

B. m₁r₁ = m₂r₂

C. m₁m₂ = r₁r₂

D. None of these

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4

Coriolis component acts

A. Perpendicular to sliding surfaces

B. Along sliding surfaces

C. Somewhere in between above two

D. None of the above

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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

When a body moves with simple harmonic motion, the product of its periodic time and frequency is equal to

A. Zero

B. One

C. π/2

D. π

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4

The pressure angle of a cam is the angle between the direction of the follower motion and a normal to the

A. Pitch circle

B. Base circle

C. Pitch curve

D. Prime circle

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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

For a kinematic chain to be considered as mechanism

A. Two links should be fixed

B. One link should be fixed

C. None of the links should be fixed

D. There is no such criterion

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4

Typewriter constitutes

A. Machine

B. Structure

C. Mechanism

D. Inversion

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Klein's construction is useful to determine

A. Velocity of various parts

B. Acceleration of various parts

C. Displacement of various parts

D. Angular acceleration of various parts

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4

The sense of coriolis component 2 ωv is same as that of the relative velocity vector v rotated at

A. 45° in the direction of rotation of the link containing the path

B. 45° in the direction opposite to the rotation of the link containing the path

C. 90° in the direction of rotation of the link containing the path

D. 180° in the direction opposite to the rotation of the link containing the path

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4

The acceleration of the reciprocating roller follower when it has contact with the straight flanks of the tangent cam, is given by

A. ω². (r₁ r₂). (1 - cos² θ)

B. ω². (r₁ + r₂). (1 + cos² θ)

C. ω². (r₁ + r₂). [(2 - cos² θ)/cos³ θ]

D. ω². (r₁ - r₂). (1 - sin² θ)

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4

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 clockwise direction, then the rubbing velocity at the pin joint O is (where r = Radius of the pin at O)

A. ω₁.ω₂.r

B. (ω₁ - ω₂)r

C. (ω₁ + ω₂)r

D. (ω₁ - ω₂)2r

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4

The ratio of the driving tensions for V-belts is __________ times that of flat belts. (Where β = Semi-angle of the groove)

A. sinβ

B. cosβ

C. cosecβ

D. secβ

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4

In a four-bar chain it is required to give an oscillatory motion to the follower for a continuous rotation of the crank. For the lengths of 50 mm of crank and 70 mm of the follower, determine theoretical maximum length of coupler. The minimum length of the coupler will be

A. 45 mm

B. Slightly less than 45 mm

C. Slightly more than 45 mm

D. 95 mm

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4

According to Kennedy's theorem, if three bodies move relatively to each other, their instantaneous centres will lie on a

A. Straight line

B. Parabolic curve

C. Triangle

D. Rectangle

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4

The equation of motion for a vibrating system with viscous damping is (d²x/dt²) + (c/m). (dx/dt) + (s/m). x = 0 If the roots of this equation are real, then the system will be

A. Over-damped

B. Under damped

C. Critically damped

D. Without vibrations

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4

In a steam engine, the distance by which the outer edge of the Dslide valve overlaps the steam port is called

A. Lead

B. Steam lap

C. Exhaust lap

D. None of these

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4

Angle of descent of cam is defined as the angle

A. During which the follower returns to its initial position

B. Of rotation of the cam for a definite displacement of the follower

C. Through which the cam rotates during the period in which the follower remains in the highest position

D. Moved by the cam from the instant the follower begins to rise, till it reaches its highest position

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4

The method of obtaining different mechanisms by fixing in turn different links in a kinematic chain, is known as

A. Structure

B. Machine

C. Inversion

D. Compound mechanism

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4

The maximum fluctuation of speed is the

A. Difference of minimum fluctuation of speed and the mean speed

B. Difference of the maximum and minimum speeds

C. Sum of maximum and minimum speeds

D. Variations of speed above and below the mean resisting torque line

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4

When the two elements of a pair have __________ when in motion, it is said to a lower pair.

A. Line or point contact

B. Surface contact

C. Body contact

D. None of these

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4

The distance by which the __________ of the D-slide valve overlaps the steam port is called exhaust lap.

A. Inner edge

B. Outer edge

C. Corners

D. None of these