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4

When the crank is at the inner dead centre, in a reciprocating steam engine, then the velocity of the piston will be

A. Minimum

B. Zero

C. Maximum

D. None of these

Correct Answer :

B. Zero


Related Questions

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4

A Hartnell governor has its controlling force (Fc) given by Fc = ar + b, where r is the radius of rotation and a and b are constants. The governor becomes isochronous when

A. a is +ve and b = 0

B. a = 0 and b is +ve

C. a is +ve and b is -ve

D. a is +ve and b is also +ve

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4

The cam follower generally used in automobile engines is

A. Knife edge follower

B. Flat faced follower

C. Spherical faced follower

D. Roller follower

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4

The velocity of a body moving with simple harmonic motion is __________ at the mean position.

A. Zero

B. Minimum

C. Maximum

D. None of these

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4

With single Hooke's joint it is possible to connect two shafts, the axes of which have an angular misalignment up to

A. 10°

B. 20°

C. 30°

D. 40°

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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 locus of a point on a thread unwound from a cylinder will be

A. A straight line

B. A circle

C. Involute

D. Cycloidal

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4

Which of the following disciplines provides study of relative motion between the parts of a machine?

A. Theory of machines

B. Applied mechanics

C. Mechanisms

D. Kinematics

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4

The load cup of a screw jack is made separate from the head of the spindle to

A. Enhance the load carrying capacity of the jack

B. Reduce the effort needed for lifting the working load

C. Reduce the value of frictional torque required to be countered for lifting the load

D. Prevent the rotation of load being lifted

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4

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

A. 1/24

B. 1/8

C. 4/15

D. 12

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4

When two pulleys of different diameters are connected by means of an open belt, the angle of contact at the ________ pulley must be taken into consideration.

A. Smaller

B. Larger

C. Either A or B

D. None of these

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4

The working depth of a gear is the radial distance from the

A. Pitch circle to the bottom of a tooth

B. Pitch circle to the top of a tooth

C. Top of a tooth to the bottom of a tooth

D. Addendum circle to the clearance circle

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4

Which of the following property of the instantaneous centre is correct?

A. A rigid link rotates instantaneously relative to another link at the instantaneous centre for the configuration of the mechanism considered.

B. The two rigid links have no linear velocity relative to each other at the instantaneous centre.

C. The velocity of the instantaneous centre relative to any third rigid link is same whether the instantaneous centre is regarded as a point on the first rigid link or on the second rigid link.

D. All of the above

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4

An involute pinion and gear are in mesh. If both have the same size of addendum, then there will be an interference between the

A. Tip of the gear tooth and flank of pinion

B. Tip of the pinion and flank of gear

C. Flanks of both gear and pinion

D. Tip of both gear and pinion

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4

The maximum efficiency of a screw jack is

A. (1 - sinφ)/(1 + sinφ)

B. (1 + sinφ)/(1 - sinφ)

C. (1 - tanφ)/(1 + tanφ)

D. (1 + tanφ)/(1 - tanφ)

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4

Klein's construction gives a graphic construction for

A. Slider-crank mechanism

B. Velocity polygon

C. Acceleration polygon

D. Four bar chain mechanism

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4

Typewriter constitutes

A. Machine

B. Structure

C. Mechanism

D. Inversion

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4

The C.G. of a link in any mechanism would experience

A. No acceleration

B. Linear acceleration

C. Angular acceleration

D. Both angular and linear accelerations

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4

The example of successfully constrained motion is a

A. Motion of an I.C. engine valve

B. Motion of the shaft between a footstep bearing

C. Piston reciprocating inside an engine cylinder

D. All of the above

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4

The relative velocity of B with respect to A in a rigid link AB is

A. Parallel to AB

B. Perpendicular to AB

C. Along AB

D. At 45° to AB

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4

If there are L number of links in a mechanism, then number of possible inversions is equal to

A. L + 1

B. L - 1

C. L

D. L + 2

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4

Which of the following is an example of a higher pair?

A. Toothed gearing

B. Belt and rope drive

C. Ball and roller bearing

D. All of these

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4

In a reciprocating steam engine, when the crank has turned from inner dead centre through an angle θ, the angular velocity of the connecting rod is given by

A. ω sinθ/(n² - sin²θ)1/2

B. ω cosθ/(n² - cos²θ)1/2

C. ω sinθ/(n² - cos²θ)1/2

D. ω cosθ/(n² - sin²θ)1/2

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4

In railway axle boxes, the bearing used is

A. Deep groove ball bearing

B. Double row self aligning ball bearing

C. Double row spherical roller bearing

D. Cylindrical roller bearing

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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 Meyer's expansion valve, the expansion valve is driven by an eccentric having an angle of advance from

A. 50°-60°

B. 60°-70°

C. 70°-80°

D. 80°-90°

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4

A fixed gear having 200 teeth is in mesh with another gear having 50 teeth. The two gears are connected by an arm. The number of turns made by the smaller gear for one revolution of arm about the centre of bigger gear is

A. 2

B. 4

C. 3

D. None of the above

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4

In a system subjected to damped forced vibrations, the ratio of maximum displacement to the static deflection is known as

A. Critical damping ratio

B. Damping factor

C. Logarithmic decrement

D. Magnification factor

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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

Which of the following is an example of sliding pair?

A. Piston and cylinder of a reciprocating steam engine

B. Shaft with collars at both ends fitted into a circular hole

C. Lead screw of a lathe with nut

D. Ball and a socket joint

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4

The mechanism forms a structure, when the number of degrees of freedom (n) is equal to

A. 0

B. 1

C. 2

D. -1