Design of Machine Elements 8

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Mechanical Engineering MCQ Question Papers: DRDO, ISRO, Interview

Subject: Design of Machine Elements 8

Part 2: List for questions and answers of Design of Machine Elements –II

Q1.To avoid interference the minimum number of teeth required on helical pinion
decreases as helix angle ________
a) Decreases
b) Increases
c) Does not affect number of teeth
d) None of the above

Q2.What is the minimum face width required for a helical gear which has helix angle of 23o and normal module of 7?
a) ≥ 64.72
b) ≥ 56.28
c) ≥ 33.35
d) ≥ 8.74

Q3.Angle made by ________ with axis of rotation is called as helix angle
a) Only helix
b) Only teeth
c) Helix or teeth
d) None of the above

Q4.A helical gear transmits power of 2050 W and has helix angle of 25 deg. If pitch line velocity is 15 m/s then what is the maximum tangential force acting on helical gear tooth? (Assume Ka = 1 & Km = 1.2)
a) 113.88 N
b) 136 N
c) 164 N
d) None of the above

Q5.Which of the following formulae of velocity factor (K) is considered if helical gears of manufactured medium accuracy are by hobbling process followed by shaving?
a) 5.6 / (5.6 + √V)
b) √5.6 / (5.6+ √V)
c) 6 / (6+V)
d) 0.85

Q6. What is the axial pitch for helical gears if helix angle is 25 deg and normal module is 7?
a) 50.55 mm
b) 52.03 mm
c) 32.15 mm
d) 11.31 mm

Q7.A straight bevel gear is manufactured by cutting process and maximum tangential force of 12000 N acts on it. What is the effective load acting between meshing teeth if pitch line velocity is 130 m/s?
a) 92.30 kn
b) 272 kn
c) 2000 N
d) Insufficient data

Q8.A bevel gear made of steel pinion and steel gear has dynamic factor C equal to
__________
a) 8900 e
b) 10000 e
c) 11500 e
d) 15000 e

Q9.What is the pitch line velocity if pinion has pitch circle diameter of 35 mm and rotates at 1000 r.p.m transmitting power of 250 kw to the gear?
a) 1.832 m/s
b) 2.5 m/s
c) 3.662 m/s
d) None of the above

Q10.A bevel gear has pitch circle diameters of pinion and gear as 20 mm and 40 mm respectively. What is the face width of bevel gear?(m =module)
a) 17.5 m
b) 10 m
c) 7.45 m
d) 3.16 m

Q11.What is the axial force acting on the pinion if a bevel gear transmits power of 20 kw with a mean pitch line velocity of 5 m/s?
a) 1865 N
b) 1801.67 N
c) 971.37 N
d) 452.96 N

Q12.Virtual number of teeth on pinion of bevel gear is calculated using the formula__________(where zp = number of teeth on pinion, γp & γg = pitch cone angle)
a) Zp / cos γp
b) Zp / cos γg
c) Zp / cos2 γp
d) Zp / cos3 γp

Q13.A pair of straight bevel gears consists of 16 pinion teeth and 42 gear teeth. What are the pitch cone angles of pinion and gear?
a) 67.60 deg & 22.39 deg
b) 52.14 deg & 37.86 deg
c) 20.85 deg & 69.14 deg
d) 35.12 deg & 54.88 deg

Q14.What is the pitch cone distance of bevel gear, if pitch circle diameter of bevel pinion and gear is 20 and 30 respectively? (Consider γp = 25 deg & Φ = 15 deg)
a) 100 mm
b) 18.02 mm
c) 21.32 mm
d) 25 mm

Q15.Which of the following bearings carry thrust load in one direction?
a) Spherical roller thrust bearings
b) Taper roller bearings
c) Both a. And b.
d) None of the above

Q16.A cylindrical roller bearing is subjected to radial force of 4500 N and application factor 1.3. What is the equivalent dynamic load acting on bearing if it has 90% reliability with desired life of 10000 hrs?
a) 3461.53 N
b) 5000 N
c) 5850 N
d) Insufficient data

Q17.Which of the following elements is not used as a roller in roller bearings?
a) Cylindrical
b) Taper
c) Spherical
d) None of the above

Q18.Load acting on bearing in its plane of rotation is called as __________
a) Axial load
b) Radial load
c) Thrust load
d) None of the above

Q19.The expected rating life of roller bearings rotating at 1000 r.p.m. Is 30000 hours and equivalent dynamic load of 4000 N acts on it. What is the basic dynamic capacity of the earing?
a) 26000.12 N
b) 30000.23 N
c) 37900.22 N
d) 48657.61 N

Q20.What will be the static capacity of single-row deep groove ball bearing having 10 balls of 15 mm? (Assume K = 62 N/mm^2)
a) 25900 kn
b) 124 kn
c) 31.00 kn
d) 27.900 kn

Part 2: List for questions and answers of Design of Machine Elements –II

Q1. Answer: b

Q2. Answer: a

Q3. Answer: c

Q4. Answer: c

Q5. Answer: a

Q6. Answer: b

Q7. Answer: b

Q8. Answer: c

Q9. Answer: a

Q10. Answer: c

Q11. Answer: d

Q12. Answer: b

Q13. Answer: c

Q14. Answer: b

Q15. Answer: c

Q16. Answer: c

Q17. Answer: d

Q18. Answer: b

Q19. Answer: c

Q20. Answer: d