# Design of Machine Tools MCQ with answer for exam and interview preperation.

1. Diameter range is high in geometric progression due to _________ spindle speed.

a. Low

b. High

c. Constant

d. None of the above

Ans: a

2. What is harmonic progression?

a. Difference between reciprocal of two successive spindle speeds is constant

b. Difference between two successive spindle speeds is constant

c. Ratio of two successive spindle speeds is constant.

d. Ratio of two successive spindle speeds is variable.

Ans: a

3. Ratio of two spindle speeds is constant in _________ progression.

a.Arithmetic

b.Geometric

c.Harmonic

d.None of the above

Ans: b

4. What is the purpose of using a gear box?

a.To increase torque

b.To increase speed

c.Converts single input speed into multiple output speeds

d.All of the above

Ans: d

5. Which of the following statements is true for structure/speed diagrams?

a.Structure diagrams gives range ratio of spindle speeds

b.Speed diagrams do not give range ratio of spindle speeds

c.Speed diagrams consider motor speed

d.All of the above

Ans: b

6. What is the maximum percentage loss of economic cutting speed if geometric progression

ratio = 1.06 ?

a.17.0 %

b.11.5 %

c.5.7 %

d.2.9 %

Ans: d

7. A machine tool has minimum speed of 100 r.p.m. How many speed steps are required by

it to achieve speed of 200 rpm? (Geometric progression ratio = 1.06)

a.11

b.12

c.13

d.14

Ans: b

8. Maximum and minimum diameter of a shaft to be machined is 100 mm and 80 mm

respectively. What is the maximum spindle speed if cutting velocity is 40 m/min?

a.120 r.p.m

b.127 r.p.m

c.160 r.p.m.

d.636 r.p.m.

Ans: c

9. Economic cutting speed is minimum if geometric ratio is _________

a.Minimum

b.Maximum

c.Equal to economic cutting speed

d.None of the above

Ans: a

10. What is the geometric progression ratio if maximum and minimum spindle speeds are

500 r.p.m and 300 r.p.m respectively? (Number of speed steps = 7)

a.0.91

b.1.5

c.1.08

d.2.0

Ans: c

11. In machine tool gear box, optimum number of speed steps with increments between---

a. 5 to 10 %

b. 10 to 15 %

c. 15 to 20 %

d. 20 to 25 %

Ans: c

12. In case of single speed gear box for every input speed there is/are only -----output speed.

a. Three

b. Two

c. One

d. None of the above

Ans: c

13. In arthmetic progression the------between any two successive spindle speed is constant.

a. Addition

b. Substraction

c. Reciprocal

d. None of the above

Ans: a

14. Multispeed drive with arithmetic progression is /are good in -----spindle speed range.

a. High

b. Low

c. Both a and b

d. None of the above

Ans: a

15. Multispeed drive with arithmetic progression is /are poor in -----spindle speed range.

a. High

b. Low

c. Both a and b

d. None of the above

Ans: b

16. In geometric progression the ------of any two successiv espindle speed is constant.

a. Addition

b. Substraction

c. Ratio

d. None of the above

Ans: c

17. Multispeed drive with geometric progression is / are poor in------spindle speed range.

a. High

b. Low

c. Both a and b

d. None of the above

Ans: b

18. Multispped drive with geometric progression gives better gear box design feature.

a. True

b. False

Ans: a

19. In which laws of stepped regulation of speeds gives constant loss of economic cutting

speed.

a. Geometric progression

b. Arthmetic progression

c. Harmonic progression

d. None of the above

Ans: a

20. In harmonic progression the -----between reciprocal of any two successive spindle speed

is constant.

a. Addition

b. Difference

c. Insufficiant data

d. None of the above

Ans: b

21. Multispeed drive with harmonic progression is / are poor in------spindle speed range.

a. High

b. Low

c. Both a and b

d. None of the above

Ans: a

22.Multispeed drive with harmonic progression is / are good in------spindle speed range.

a. High

b. Low

c. Both a and b

d. None of the above

Ans: b

23. If speed steps are obtained by arithematic or harmonic progression the number of gear

pairs required are equal to the number of speed steps.

a. This makes gear box bulky

b. Gear shifiting time consuming as well as inconvenient

c. Entire arrangement economically infeasible

d. All of the above

Ans: d

24. The constant loss of economic cutting speed over the total spindle speed range,the

spindle speed must be in----

a. Geometric progression

b. Arthmetic progression

c. Harmonic progression

d. None of the above

Ans: a

25. Compact and better gear box designed obtained in which law---

a. Geometric progression

b. Arthmetic progression

c. Harmonic progression

d. None of the above

Ans: a

26. The multispeed drive with ---- law is commanly used in machine tool drive.

a. Arthmetic progression

b. Harmonic progression

c. Geometric progression

d. None of the above

Ans: c

27. The range ratio for the multispeed gear box is ---

a. The ratio of maximum output speed of gear box to the minimum output speed of the gear

box.

b. The ratio of minimum output speed of gear box to the maximum output speed of the gear

box.

c. Insufficiant data

d. None of the above

Ans: a

28. The value of range ratio Rn is large for general purpose machine tools--

a. True

b. False

c. Insufficiant data

d. None of the above

Ans: a

29. The value of range ratio Rn is small for secial purpose machine tools--

a. True

b. False

c. Insufficiant data

d. None of the above

Ans: a

30. The smaller value of geometric progression ratio ф is / are used in---

a. Large sized heavy duty machine

b. Automats

c. Both a and b

d. None of the above

Ans: c

31.The larger value of geometric progression ratio ф is used in---

a. Small sized special purpose machine tools

b. Large sized heavy duty machine

c. Automats

d.None of the above

Ans: a

32. For the higher the value of geometric progression ratio ф the loss of economic cutting

speed is--

a. Low

b. High

c. Moderate

d. Insufficiant data

Ans: a

33. For the lower value of geometric progression ratio ф the loss of economic cutting speed

is--

a. Minimum

b. Maximum

c. Moderate

d. Insufficiant data

Ans: b

34. For the lower value of geometric progression ratio ф the number of speed steps or

spindle speeds Z is---

a. Large

b. Small

c. Insufficiant data

d. None of the above

Ans: a

35. For the higher value of geometric progression ratio ф the number of speed steps or

spindle speeds Z is---

a. High

b. Low

c. Insufficiant data

d. None of the above

Ans: b

36. Standard values of geometric progression ratio ф for series ф20/3 equal to----

a. 1.41

b. 1.56

c. 1.78

d. 2

Ans: a

37. In order to compromise between the loss of economic cutting speed and the compactness of the drive the value of ф is selected.

a. 2 < ф ≤ 3

b. 3 < ф ≤ 4

c. 4 < ф ≤ 5

d. 1 < ф ≤ 2

Ans: d

38. Recommende value of ф for heavy duty machine tools and automats--

a. 1.12

b. 1.26

c. 1.14

d. 1.58

Ans: a

39. Recommende value of ф for medium size general purpose machine tools--

a. 1.12

b. 1.26

c. 1.14

d. 1.58

Ans: c

40. Number of spindle speed stepsin machine tool gear box indicated by letter--

a. Z

b. ф

c. Rn

d. None of the above

Ans: a

41. The normally selected value/ s of Z is /are --

a. 4

b. 6

c. 8

d. All of the above

Ans: d

42. letter P indicates in machine tool gear box as ?

a. Number of speed steps per stage

b. Number of spindle speed steps

c. Geometric ratio

d. Range ratio

Ans: a

43. When structural formulae to be feasible , the product PkXk must be a factor of Z--

a. True

b. False

c. Insufficiant data

d. None of the above

Ans: a

44. For machine tool gear box the transmission range should not be grater than ---

a. 9

b. 10

c. 11

d. 8

Ans: d

45. In structural digram, Each zone between two adjacent vertical lines reperesents a---

a. Transmission group

b. Stage

c. Both a and b

d. None of the above

Ans: c

46.In speed diagram, Each horizontal line represents a---

a. Spindle speed

b. Spindle steps

c. Both a and b

d. None of the above

Ans: a

47. What is /are the limitation/s of structure diagram---

a.It gives, The spindle speeds

b. It gives, The motor speeds

c. It gives ,The geometric progression ratio

d. All of the above

Ans: d

48. Number of speed steps in any stage should not be more than---

a. 3

b. 4

c. 5

d. 6

Ans: a

49. The speed ratio in last stage should be as ---------as possible.

a. Maximum

b. Minimum

c. Insufficient data

d. None of the above

Ans: a

50. Sailent feature/ s of speed diagram is / are---

a. It gives ,The number of shaft in the gera box

b. It gives ,The number of gears on each shaft

c. It gives , the spindle speeds

d. All of the above

Ans: d

51. To avoid interference on gears ,the number of teeth on the smallest gear of the gear box

is---

a. 21

b. 16

c. 18

d. 20

Ans: c

52. If gear pairs on parallel shafts have same module the sum of number of teeth on mating

gear must be same---

a. Correct

b. Incorrect

c. Insufficiant data

d. None of the above

Ans: a

53. Minimum difference between number of teeth of adjacent gears in a change gera block

must be at least---

a. 6

b. 3

c. 4

d. 5

Ans: c

54. Spacing between two adjacent gear on the shaft must be grater than -----the face width.

a. Twice

b. Thrice

c. Insufficiant data

d. none of the above

Ans: a

55. If the line is inclined upwards from left to right in speed diagram repersent the----

a. Increment in speed

b. Decrement in speed

c. There is no speed change

d. None of the above

Ans: a

56. If the line is inclined downwards from left to right in speed diagram repersent the----

a. Increment in speed

b. Decrement in speed

c. There is no speed change

d. None of the above

Ans: b

57. If the line is straight from left to right in speed diagram repersent the----

a. Increment in speed

b. Decrement in speed

c. There is no speed change

d. None of the above

Ans: c

58. Conditiom for optimum structure diagram---

a. X1 < X2 < X3

b. X3 < X2 < X1

c. X2 < X1 < X3

d. X3 < X1 < X2

Ans: a

59. Letter N indicate in machine tool gear box design ?

a. Number of stages of gear box

b. Number of spindle speed steps

c. Range ratio

d. geometric progression ratio

Ans: a

60. Range ratio for central lathe is --

a. 8-10

b. 15-25

c. 15-30

d. 40-60

Ans: d

61. Deviation of actual spindle speeds from calculated spindle speeds must not exceed--

a. 10 (ф-1)

b. 20 (ф-1)

c. 30 (ф-1)

d. 40 (ф-1)

Ans: a

62. The speed diagram contains the number of horizontal lines required for locating ?

a. All spindle speds

b. Electric motor speed

c. Both a and b

d. None of the above

Ans: c

63. Zth Spindle speed in Arithematic progression ----

a. nz = nmax- nmin/(Z-1)

b. nz = (nmax/nmin)

1/Z-1

c. nz = 1/nz - 1/n1

d. None of the above

Ans: a

64. Zth Spindle speed in geometric progression ----

a. nz = nmax- nmin/(Z-1)

b. nz = (nmax/nmin)

1/Z-1

c. nz = 1/nz - 1/n1

d. None of the above

Ans: b

65. Zth Spindle speed in harmonic progression ----

a. nz = nmax- nmin/(Z-1)

b. nz = (nmax/nmin)

1/Z-1

c. nz = 1/nz - 1/n1

d. None of the above

Ans: c

66. ф Geometric progression ratio is equal to

a. ф = (nmax/nmin)

1/Z-1

b. ф = Rn

1/Z-1

c. Both a and b

d. None of the above

Ans: c