81. Two pulleys of radii r1 and r2 and at distance x apart are connected by means of a cross belt drive. The length of the belt is
✅ The correct answer is option A.
Theory of machines MCQs
82. The displacement of a flat-faced follower when it has contact with the flank of a circular arc cam, is given by (where R = Radius of flank, r1 = Minimum radius of the cam, and θ = Angle turned through by the cam)
R(1 – cos θ)
(R – r1)(1 – cos θ)
R(1 – sin θ)
(R – r1)(1 – sin θ)
✅ The correct answer is option B.
83. A system in dynamic balance implies that
the system is critically damped
there is no critical speed in the system
the system is also statically balanced
there will absolutely
✅ The correct answer is option C.
84. V-belts are usually used for
long drives
short drives
long and short drives
none of these
✅ The correct answer is option B.
85. If ω/ωn is very low for a body vibrating under steady state vibrations, the phase angle for all values of damping factors, will tend to approach
0°
90°
180°
360°
✅ The correct answer is option A.
86. When a body is subjected to longitudinal vibrations, the stress induced in a body will be tensile or compressive stress.
Correct
Incorrect
✅ The correct answer is option A.
87. The friction experienced by a body, when at rest, is known as static friction.
Yes
No
✅ The correct answer is option A.
88. The two links are said to have a pure rolling contact, when their instantaneous centre __________ on their point of contact.
lies
does not lie
✅ The correct answer is option A.
89. The maximum gyroscopic couple acting on the ship tends to shear the holding down bolts.
Correct
Incorrect
✅ The correct answer is option A.
90. The frictional torque transmitted in a conical pivot bearing, considering uniform wear, is
μ W R cosec α
μ W R cosec α
μ W R cosec α
μ W R cosec α
✅ The correct answer is option A.