TORSION SHAFTS MULTIPLE CHOICE QUESTIONS (MCQ) WITH ANSWERS

 TORSION SHAFTS

MULTIPLE CHOICE QUESTIONS (MCQ)

WITH ANSWERS

MCQ help in

the design and manufacture of shafts.

Maximum practical failures occur in

shafts because of reversal stresses. Thus

its design requires special attention to

make it really safe under all conditions.

Fig. Torsion of Shafts (a) Shaft is under Torque T, (b) Shaft cross section

_{1. Variation of shear stress in torsion of shaft is}

(a) Parabolic
(b) Linear
(c) Cubical
(d) None
(Ans: b)

Fig. Shear stress              Fig. Shear strain variation

variation in a solid shaft        in a solid shaft

2. Power in watts in a shaft having N RPM is 

(a) Power = 2π NT/60

 (b) Power = 2π N T
(c) Power = 2000 π N T/60
(d) None
(Ans: a)

3. Equivalent torque in a shaft subjected to axial load P, torque T and bending moment M is

(a) T_eq = (Pa2 + M2 + T2)
(b) T_eq = (Pa2 + M2 + T2)^0.5
(c)T_eq = ( M2 + T2)^0.5
(d) None
(Ans: c)

4. Equivalent bending moment in a shaft subjected to axial load P, torque T and bending moment M is

(a) M_eq = 0.5 [M + (M2 + T2)0.5]^0.5
(b) M_eq = 0.5 [M + (M2 + T2)^0.5]
(c) M_eq = ( M2 + T2)^0.5
(d) None
(Ans: b)

5. A power transmitting ductile material shaft under P, T and M will fail under

(a) Tensile considerations only
(b) Compressive considerations only
(c) Shear considerations only
(d) None
(Ans: c)

6. Design a ductile material power transmitting shaft under P, T and M using

(a) Rankine theory
(b) Guest Theory
(c) Haigh theory
(d) None

(Ans: b)

7. From strength point of view, whether hollow or solid power transmitting shaft is preferable

(a) Solid shaft
(b) Hollow shaft
(c) Both solid as well as hollow shaft
(d) None

(Ans: b)

8. The strain energy will be higher in which shaft under the same torque

(a) Solid shaft
(b) Hollow shaft
(c) Same in Solid as well as hollow shaft
(d) None

(Ans: b)

 9. Design a shaft for

 (a) Strength alone
(b) Stiffness alone
(c) Both for strength and stiffness
(d) None

(Ans: c)

10. Actual stress in the bolts of a flanged coupling of a shaft will be

(a) More than the designed strength
(b) Less than the designed strength
(c) Neither more nor less than the designed strength
(d) None

(Ans: b)

11. Torsion equation is

1. Firstly          T/I =σ/r=Gθ/L

2. Secondly      T/L=τ/r =Gθ/L

3. Thirdly          T/J =τ/y =Gθ/L

4. None

ANS: (d)

12. Torsion equation is

1. Firstly            T/I =σ/r=Gθ/L

2. Secondly        T/L=τ/r =Gθ/L

3. Thirdly            T/J =τ/r =Gθ/L

4. None

ANS: (c)

13. Strain energy in a solid shaft is

1. Firstly      (τ/4G) volume

2. Secondly    (τ²/4G) volume

3. Thirdly         (τ³/4G) volume

4. None

ANS: (b)

14. Torsional stiffness of a shaft is

1. Firstly      Gθ

2. Secondly   Gγ

3. Thirdly       GJ

4. None

ANS: (c )

15. Maximum number of Loads acting on the shafts is

1. Torsion & bending

2.  Axial & Torsion

3.   Bending, axial & torsion

4. None

ANS: (c )

16. Due to increase of torque, the shaft shear takes place

1. Parallel to the axis

2. Perpendicular to the axis

3. Both parallel & perpendicular to the axis

4. None

ANS: (b)

17. The material of the shaft is

1. Homogeneous and continuous

2. Isotropic & Homogeneous 

3. Homogeneous, isotropic & continuous

4. None

ANS: (c )

18. Distance between two transverse sections is

1. Variable

2. Constant

3. Variable & constant

4. None

ANS: (b)

19. Maximum shear stress induced should be less or equal to the

1. Ultimate limit

2. Yield limit

3. Elastic limit

4. None

ANS: (c )

20. Polar moment of inertia of a solid shaft is

1. Firstly          (π/64) d³

2. Secondly     (π/32) d⁴

3. Thirdly          (π/32)d³

4. None

ANS: (b)

21. Polar moment of inertia of a hollow shaft is

• Firstly          (π/64) D³ –d³)

• Secondly      (π/32) D⁴ –d³)

• Thirdly         (π/32)D⁴ –d⁴)

• None

ANS: (c)

22. Conditions for two shafts connected in series are

1. Firstly       T₁=T₂=T, &θ₁ =θ₂

2. Secondly  T₁+T₂=T, &θ₁ =θ₂

3. Thirdly      T₁=T₂=T, &θ₁ +θ₂=θ

4. None

ANS: (c )

23. Conditions for two shafts connected in parallel are

(a) Firstly       T₁=T₂=T, &θ₁ =θ₂

(b) Secondly   T₁+T₂=T, &θ₁ =θ₂

© Thirdly          T₁=T₂=T, &θ₁ +θ₂=θ

(d)None

ANS: (b )

24. Strain energy in a solid shaft is

1. Firstly      τ/4G

2. Secondly  τ²/4G

3. Thirdly      τ³/4G

4. None

ANS: (d)

25. In torsion of shafts, variation of shear stress is along the

1. Radius

2. Length

3. Both (a) & (b)

4.  None

ANS: (a)

26. Shear stress in a shaft depends on

1. Torque and radius

2. Radius & Polar moment of inertia

3. Radius, torque & polar moment of inertia

4. None

ANS: ©

27. Polar moment of inertia depends on the

1. Material of the shaft

2. Geometry of the shaft

3. Both (a) & (b)

4. None

ANS: (b)

28. A force which causes shear stress in a shaft is 

1. Parallel to the area of cross-section

2. Tangent to the area of cross-section

3. Both (a) & (b)

4. None

ANS: (b)

29. In calculating critical speed of a shaft, consider

1. Lowest frequency

2. Highest frequency

3. Both (a) & (b)

4. None

ANS: (a)

30. Calculate critical speed of a shaft by

1. Rayleigh-Ritz method

2. Dun Kerley’s method

3. Both (a) & (b)

4. None

ANS: (c)

31. Critical speed of a shaft ( RPM) with static deflection ‘y’ is 

1. (g/y)⁵ x 60/π

2. (g/y _max)⁵ x 30/π

3. (g/T)⁵ x 90/π

4. None

ANS: (b)

32. Critical speed of a shaft depends upon

1. Amount of unbalance & kind of support

2. Length & diameter of the shaft

3. Both (a) & (b)

4. None

ANS: (c)

33. The reduction in weight of hollow shaft with same outer diameter, length, material.

The inside diameter is half of the outer diameter is

1. 75 %

2. 50 %

3. 25%

4. None

ANS: (c)

34. Modulus of shear/Young’s modulus of a shaft is

1. >1

2. <1

3. =1

4. None

ANS: (b)

35. Shafts in series and parallel is like

1. Resistances in series and parallel

2. Cells in series and parallel

3. Both (a) & (b)

4. None

ANS: (d)

36. A composite shaft consists of

1. Two materials

2. Two diameters

3. Both (a) & (b)

4. None

ANS: (c)

37. Torque in Shafts in parallel acts at the

1. Center of shaft

2. Common radius

3. Outermost radius

4. None

ANS: (b)

38. In a shaft with negligible bending moment and axial thrust, principal stresses are

1. > shear stress

2. < shear stress

3. = shear stress

4. None

ANS: (c)

39. Torsional section modulus of a shaft under torsion is

1. J/R

2. R/J

3. J/D

4. None

ANS: (a)

40. A shaft of adequate stiffness has a twist of 1⁰ in a length of

1. 10 d

2. 20 d

3. 30 d

4. None

ANS: (b)

 

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