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