Machine Design Multiple Choice Questions on “Belt Constructions”.
1. The layer of a belt is generally called as
a) Ply
b) Layer
c) Segment
d) Sediment
Answer: a
Clarification: Terminology.
2. Velocity ratio for chain drive is lesser than that for belts.
a) Yes
b) No
c) In some cases
d) Can’t be determined
Answer: b
Clarification: Velocity ratio for chain drives is about 15:1 while for belts it is around 7:1.
3. Fabric rubber belts are not widely used as they can’t be operated at high speeds.
a) They can’t be used at velocities 50m/s
b) They can be used at high velocities
c) Limiting velocity is 20m/s
d) None of the listed
Answer: b
Clarification: These belts can be operated at 300m/s.
4. Power transmitting capacity of V belts is more than that of flat belt.
a) Yes
b) No
c) Only for V angle > 15
d) None of the listed
Answer: a
Clarification: Coefficient of friction is 2.92times of flat belts in V belts for identical materials.
5. The optimum velocity of the belt for maximum transmission is given by √P/6m.
a) Yes
b) No, by replacing 6 by 3
c) Replacing 6 by 9
d) None of the listed
Answer: b
Clarification: It is given by √P/3m.
6. Creep is the slight absolute motion of the belt as it passes over the pulley.
a) Yes
b) No, it is a relative motion
c) None of the listed
d) It is absolute motion
Answer: b
Clarification: It is a relative and not absolute motion.
7. In horizontal belt, the loose side is generally kept on the bottom.
a) True
b) False
Answer: b
Clarification: Loose side is kept on the top so that arc of contact increases and hence efficiency of the drive increases.
8. Vertical drives are preferred over horizontal.
a) True
b) False
Answer: b
Clarification: In vertical drive, gravitational force on the belt causes slip which reduces the efficiency.
9. The law of belting states that the centreline of the belt when it approaches a pulley must not lie in the midplane of the pulley.
a) True
b) False
Answer: a
Clarification: The centreline must lie in the midplane.
10. It is possible to use the belting reverse direction without violating the law of belting.
a) True
b) False
Answer: b
Clarification: Law of belting is violated if belt is used in reverse direction.
11. A shorter centre distance is always preferred in belt drives.
a) Yes due to stability
b) No due to stability
c) Yes due to instability
d) No due to instability
Answer: a
Clarification: It is more stable and compact.
12. If velocity ratio is less than 3, then centre distance is given by D+.5d.
a) True
b) False
Answer: b
Clarification: It is given by D+1.5d.
13. If velocity ratio is more than 3, then centre distance is given by 2D.
a) By 3D
b) By D
c) By 4D
d) By 5D