Manufacturing Considerations in Machine Design
1. Stressed parts are always kept in tension.
a) True
b) False
Answer: A
Explanation: Cast iron has more compressive strength.
2. Shot blasting process improves the endurance limit of the component.
a) True
b) False
Answer: A
Explanation: Shot blasting employs throwing wheel which imparts strength to the material.
3. Which process allows controlling grain structure of the product?
a) Casting
b) Forging
c) None of the mentioned
d) Die Casting
.
Answer: B
Explanation: In casting metal is in fluid state and hence impossible to control the grain structure.
4. While designing a forging, the profile is selected such that the fibrous lines are parallel to the tensile forces and perpendicular to shear forces.
a) True
b) False
.
Answer: A
Explanation: Tensile load is applied parallel to the grain structures.
5. Cast surfaces have good finishing.
a) True
b) False
.
Answer: B
Explanation: Cavity is surrounded by sand and hence not good finish is obtained.
6. In forging, metal is in which of the following stage?
a) Elastic
b) Plastic
c) Can be in any stage
d) Rigid
.
Answer: B
Explanation: Forging is the working of metal in plastic range.
7. Forged components can be held between close limits.
a) True
b) False
.
Answer: A
Explanation: There is no shrinkage problems and hence less tolerances.
8. Among casting, forging and forging which has the slowest rate of production?
a) Casting
b) Forging
c) Machining
d) All have equal rate of production
.
Answer: C
Explanation: Machining each part is very time consuming.
9. In manual assembly, cost of screw is higher than the cost of driving a screw.
a) True
b) False
.
Answer: B
Explanation: Generally manufacturing screw is cheaper than driving it.
10. Maximum carbon content in welding is usually limited to
a) 0.22%
b) 0.8%
c) 1.5%
d) 2%
.
Answer: A
Explanation: With increase of carbon, welding becomes difficult as weld becomes susceptible to cracks.
11. Which of the following is not a classification of fit?
a) Clearance
b) Transition
c) Interference
d) Enjoining
.
Answer: D
Explanation: Simple classification of fits is down in 3 categories.
12. Which of the following always provides a positive clearance between the hole and the shaft over the entire range of tolerances?
a) Clearance
b) Transition
c) Interference
d) None of the mentioned
.
Answer: A
Explanation: Clearance positive imparts a positive clearance.
13. In this case, tolerance zone of hole is entirely below that of the shaft.
a) Clearance
b) Interference
c) Enjoining
d) Non of the mentioned
.
Answer: B
Explanation: Interference fit provides a positive clearance and hence tolerance zone of hole is below that of shaft.
14. Which of the following are true for system of tolerances to the shaft and the hole?
a) In hole-basis system, various shafts are associated with a single hole
b) In hole-basis system as well as shaft-basis system, various shafts are associated with multiple holes
c) In shaft-basis system, various shafts are associated with a single hole
d) None of the mentioned
.
Answer: A
Explanation: As per the standards.
15. The description of tolerances consists of two parts namely?
a) Fundamental deviation and magnitude of tolerance
b) Magnitude of deviation and magnitude of tolerance
c) Mean deviation and magnitude of tolerance
d) Fundamental deviation and tolerance
.
Answer: A
Explanation: Fundamental deviation and magnitude of tolerance are decrypted in the tolerance.
16. Which of the following are true for fundamental deviation?
a) Gives location of tolerance zone
b) Capital letter is used for both holes and shafts
c) Small letter is used for both holes and shaft
d) None of the mentioned
.
Answer: A
Explanation: Tolerance zone is depicted by deviation while magnitude is depicted by grade.
17. How many grades of tolerances are there according to BIS system fits and tolerances?
a) 12
b) 14
c) 16
d) 18
.
Answer: D
Explanation: As per the standard.
18. Tolerance for a shaft of 50mm diameter as the basic size, with the fundamental deviation denoted by g and tolerance of grade 7 is represented as?
a) g50,7
b) 50g7
c) 7g50
d) None of the mentioned
.
Answer: B
Explanation: First fundamental deviation is written followed by diameter and grade.
19. The temperature at which new stress free grains are formed in the metal is called the ______ temperature.
a) Recrystallization
b) Crystallization
c) Solidification
d) None of the mentioned
.
Answer: A
Explanation: Definition of recrystallization temperature.
20. Hot working or cold working, which reduces strain hardening and residual stresses.
a) Hot working
b) Cold working
c) Both have equal effect
d) Impossible to detect
.
Answer: A
Explanation: In hot working grains are re arranges as per requirement and no residual stresses.
21. Hot rolled components have better toughness and ductility.
a) True
b) False
.
Answer: A
Explanation: Hot working refines grain structure an hence improves ductility and toughness.
22. Hot rolled components have better surface finish than cold rolled components.
a) True
b) False
.
Answer: B
Explanation: Cold working gives better surface finish.
