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4

A point B on a rigid link AB moves with respect to A with angular velocity ω rad/s. The radial component of the acceleration of B with respect to A, is (where vBA = Linear velocity of B with respect to A)

A. vBA × AB

B. vBA /AB

C. BA

D. BA /AB

Correct Answer :

D. v²BA /AB


Related Questions

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4

The lead screw of a lathe with nut forms a

A. Rolling pair

B. Sliding pair

C. Screw pair

D. Turning pair

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4

When a point moves along a straight line, its acceleration will have

A. Radial component only

B. Tangential component only

C. Coriolis component only

D. Radial and tangential components both

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4

Open pairs are those which have

A. Point or line contact between the two elements when in motion

B. Surface contact between the two elements when in motion

C. Elements of pairs not held together mechanically

D. Two elements that permit relative motion

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4

Cam size depends upon

A. Base circle

B. Pitch circle

C. Prime circle

D. Outer circle

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4

In a coupling rod of a locomotive, each of the four pairs is a ________ pair.

A. Sliding

B. Turning

C. Rolling

D. Screw

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4

The sensitiveness of the governor __________ as the speed range decreases.

A. Remains unaffected

B. Decreases

C. Increases

D. None of these

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4

A slider crank chain consists of following numbers of turning and sliding pairs

A. 1, 3

B. 2, 2

C. 3, 1

D. 4, 0

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4

A motor car moving at a certain speed takes a left turn in a curved path. If the engine rotates in the same direction as that of wheels, men due to centrifugal forc

A. The reaction on me inner wheels increases and on the outer wheels decreases

B. The reaction on the outer wheels increases and on the inner wheels decreases

C. The reaction on the front wheels increases and on the rear wheels decreases

D. The reaction on the rear wheels increases and on the front wheels decreases

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4

A rotor which is balanced statically but not dynamically is supported on two bearings L apart and at high speed of the rotor, reaction on the left bearing is R. The right side of the bearing is shifted to a new position 2L apart from the left bearing. At the same rotor speed, dynamic reaction on the left bearing in the new arrangement will

A. Remain same as before

B. Become equal to 2R

C. Become equal to R/2

D. Become equal to R/4

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4

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

In a disc clutch, if there are n₁ number of discs on the driving shaft and n₂ number of discs on the driven shaft, then the number of pairs of contact surfaces will be

A. n₁ + n₂

B. n₁ + n₂ + 1

C. n₁ + n₂ - 1

D. n₁ + n₂ - 2

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4

The frictional torque transmitted by a disc or plate clutch is same as that of

A. Flat pivot bearing

B. Flat collar bearing

C. Conical pivot bearing

D. Truncated conical pivot bearing

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4

The frictional torque transmitted in a flat pivot bearing, considering uniform wear, is (where μ = Coefficient of friction, W = Load over the bearing, and R = Radius of bearing surface)

A. (1/2) μ W R

B. (2/3) μ W R

C. (3/4) μ W R

D. μ W R

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4

When a point at the end of a link moves with constant angular velocity, its acceleration will have

A. Radial component only

B. Tangential component only

C. Coriolis component only

D. Radial and tangential components both

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4

A foot step bearing and rotor of a vertical turbine form examples of

A. Incompletely constrained motion

B. Partially constrained motion

C. Completely constrained motion

D. Successfully constrained motion

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4

In which of the following type of gear train the first gear and the last gear are co-axial.

A. Simple gear train

B. Compound gear train

C. Reverted gear train

D. None of the above

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4

In a screw jack, the effort required to lift the load W is given by (where α = Helix angle, and φ = Angle of friction)

A. P = W tan(α - φ)

B. P = W tan(α + φ)

C. P = W tan(φ - α)

D. P = W cos(α + φ)

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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 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)

A. ω₁.ω₂.r

B. (ω₁ - ω₂) r

C. (ω₁ + ω₂) r

D. (ω₁ - ω₂) 2r

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4

Which one of the following is an exact straight line mechanism using lower pairs?

A. Watts mechanism

B. Grasshopper mechanism

C. Roberts mechanism

D. Peaucelliers mechanism

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4

Which of the following is false statement in respect of differences between machine and structure?

A. Machines transmit mechanical work, whereas structures transmit forces

B. In machines, relative motion exists between its members, whereas same does not exist in case of structures

C. Machines modify movement and work, whereas structures modify forces

D. Efficiency of machines as well as structures is below 100%

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4

The velocity of piston in a reciprocating steam engine is given by (where ω = Angular velocity of crank, r = Radius of crank pin circle, θ = Angle turned by crank from inner dead centre, and n = Ratio of length of connecting rod to the radius of crank)

A. ωr [sin θ + (sin 2θ/n)]

B. ωr [cos θ + (cos 2θ/n)]

C. ω²r [sin θ + (sin 2θ/n)]

D. ω²r [cos θ + (cos 2θ/n)]

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4

A body in motion will be subjected to coriolis acceleration when that body is

A. In plane rotation with variable velocity

B. In plane translation with variable velocity

C. In plane motion which is a resultant of plane translation and rotation

D. Restrained to rotate while sliding over another body

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4

To obviate axial thrust, following gear drive is used

A. Double helical gears having opposite teeth

B. Double helical gears having identical teeth

C. Single helical gear in which one of the teeth of helix angle a is more

D. Mutter gears

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4

Which of the following has sliding motion?

A. Crank

B. Connecting rod

C. Crank pin

D. Crosshead

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4

A point on a connecting link (excluding end points) of a double slider crank mechanism traces a

A. Straight line path

B. Hyperbolic path

C. Parabolic path

D. Elliptical path

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4

Which of the following statement is correct?

A. The power absorbed in operating the piston valve is less than D-slide valve

B. The wear of the piston valve is less than the wear of the D-slide valve

C. The D-slide valve is also called outside admission valve.

D. All of the above

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4

When a ship travels in a sea, which of the effect is more dangerous

A. Steering

B. Pitching

C. Rolling

D. All of the above

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4

To connect two parallel and coplanar shafts the following type of gearing is used

A. Spur gear

B. Bevel gear

C. Spiral gear

D. None of the above

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4

A kinematic chain is known as a mechanism when

A. None of the links is fixed

B. One of the links is fixed

C. Two of the links are fixed

D. None of these