Machine Design Multiple Choice Questions on “Cotter Joints”.
1. Cotter joint is used when the members are subjected to which type of stresses?
a) Axial tensile
b) Axial compressive
c) Axial tensile or compressive
d) None of the mentioned
Answer: c
Clarification: Cotter joint is used when axial forces are applied.
2. The principle of wedge action is used in cotter joint.
a) True
b) False
Answer: a
Clarification: Wedge action imparts tightening to the cotter joint.
3. Can the cotter joint be used to connect slide spindle and fork of valve mechanism?
a) True
b) False
Answer: a
Clarification: As long as axial forces act, cotter joint can be employed.
4. Which of the following is not a part of cotter joint?
a) Socket
b) Spigot
c) Cotter
d) Collar
Answer: d
Clarification: There is no point of mentioning collar alone in a cotter joint. It has to be a spigot collar or socket collar.
5. Cold riveting holds the connected parts better than hot riveting.
a) True
b) False
Answer: b
Clarification: The compression of connected parts in hot riveting causes friction, which resist sliding of one part with respect to other. This force is greater in hot riveting.
6 .In cold riveting like hot riveting shank is subjected to majorly tensile stress.
a) True
b) False
Answer: b
Clarification: In cold riveting there is no reduction in length and hence no tensile stress. Shear stress dominates.
7. Determine the width of the cotter used in cotter joint connecting two rods subjected to axial load of 50kN and permissible shear stress in cotter is 50N/(mm² ). Given thickness of cotter=10mm
a) 5omm
b) 100mm
c) 150mm
d) 25mm
View Answer
Answer: a
Clarification: Cotter is subjected to double shear hence width=P/(2*τ*t).
8. If joint is to fail by crushing of socket collar then estimate the diameter of socket collar. Given Permissible compressive stress= 126.67 N/mm².; Spigot dia=65mm; thickness 0f collar=15mm
a) 131mm
b) 139mm
c) 141mm
d) 149mm
Answer: a
Clarification: Compressive stress= P/ [(socket dia-spigot dia)*thickness].
9. Cotter joint can be used to connect two rods for torque transmission purpose.
a) True
b) False
Answer: b
Clarification: Cotter Joint is never used to connect two rods for torque transmission purpose.
10. Thickness of plate is required more in welding than in riveting.
a) True
b) False
Answer: b
Clarification: In riveting, cross section is weakened due to the holes and to compensate this, thicker plates are required in riveting.