The magnitude of velocities of the points on a rigid link is
A. Directly proportional to the distance from the points to the instantaneous center and is parallel to the line joining the point to the instantaneous center
B. Directly proportional to the distance from the points to the instantaneous center and is perpendicular to the line joining the point to the instantaneous center
C. Inversely proportional to the distance from the points to the instantaneous center and is parallel to the line joining the point to the instantaneous center
D. Inversely proportional to the distance from the points to the instantaneous center and is perpendicular to the line joining the point to the instantaneous center
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When the belt is stationary, it is subjected to some tension known as initial tension. The value of this tension is equal to the
A. Tension in the tight side of the belt
B. Tension in the slack side of the belt
C. Sum of the tensions on the tight side and slack side of the belt
D. Average tension of the tight side and slack side of the belt
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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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The ratio of maximum fluctuation of speed to the mean speed is called
A. Fluctuation of speed
B. Maximum fluctuation of speed
C. Coefficient of fluctuation of speed
D. None of these
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Klein's construction can be used to determine acceleration of various parts when the crank is at
A. Inner dead centre
B. Outer dead centre
C. Right angles to the link of the stroke
D. All of the above
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The advantage of the piston valve over the slide valve is that in the former case
A. Wear is less
B. Power absorbed is less
C. Both wear and power absorbed are low
D. The pressure developed being high provides tight sealing
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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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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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When two links are connected by a pin joint, their instantaneous center lies
A. On their point of contact
B. At the center of curvature
C. At the center of circle
D. At the pin joint
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When a slider moves on a fixed link having curved surface, 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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Inertia force acts
A. Perpendicular to the acceleration force
B. Along the direction of acceleration force
C. Opposite to the direction of acceleration force
D. None of the above
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The total number of instantaneous centers for a mechanism consisting of n links are
A. 2 n
B. n
C. n - 1
D. 2 n ( n − 1 )
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The rotating shafts tend to vibrate violently at whirling speeds because
A. The system is unbalanced
B. Bearing centre line coincides with the axis
C. The shafts are rotating at very high speeds
D. Resonance is caused due to the heavy mass of the rotor
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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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The efficiency of a screw jack is maximum, when (where α = Helix angle and φ = Angle of friction)
A. α = 4 5 ∘ + 2 φ
B. α = 4 5 ∘ − 2 φ
C. α = 9 0 ∘ + φ
D. α = 9 0 ∘ − φ
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A body will begin to move down an inclined plane, if the angle of inclination of the plane is ________ the angle of friction.
A. Equal to
B. Less than
C. Greater than
D. None of these
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The frictional torque transmitted in a conical pivot bearing, considering uniform pressure, is (where R = Radius of shaft and α = Semi-angle of the cone)
A. 2 1 μ WRcosec α
B. 3 2 μ WRcosec α
C. 4 3 μ WRcosec α
D. μ WRcosec α
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A point on a link connecting double slider crank chain traces a
A. Ellipse
B. Circle
C. Parabola
D. Hyperbola
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The Whitworth quick return motion mechanism is formed in a slider crank chain when the
A. Coupler link is fixed
B. Longest link is a fixed link
C. Slider is a fixed link
D. Smallest link is a fixed link
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The arrangement is called bevel gearing, when two __________ are connected by gears.
A. Intersecting and coplanar shafts
B. Non-intersecting and non-coplanar shafts
C. Parallel and coplanar shafts
D. Parallel and non-coplanar shafts
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