# Torsion - Mechanical Engineering (MCQ) questions and answers

1)   What is the shear stress acting on the outer surface of a hollow shaft subjected to a torque of 100 Nm?
(The inner and outer diameter of the shaft is 15 mm and 30 mm respectively.)

a. 50.26 N/mm2
b. 40.24 N/mm2
c. 20.120 N/mm2
d. 8.74 N/mm2
 Answer  Explanation ANSWER: 20.120 N/mm2 Explanation: No explanation is available for this question!

2)   Torque and bending moment of 100 kN.m and 200 kN.m acts on a shaft which has external diameter twice of internal diameter. What is the external diameter of the shaft which is subjected to a maximum shear stress of 90 N/mm2?

a. 116.5 mm
b. 233.025 mm
c. 587.1 mm
d. 900 mm
 Answer  Explanation ANSWER: 587.1 mm Explanation: No explanation is available for this question!

3)   Which of the following assumptions are made in torsion theory?

a. Shaft is perfectly straight
b. Material of the shaft is heterogeneous
c. Twist cannot be uniform along the length of the shaft
d. All of the above
 Answer  Explanation ANSWER: Shaft is perfectly straight Explanation: No explanation is available for this question!

4)   A member subjected to couple produces rotational motion about its longitudinal axis called as ________

a. torsion
b. twisting moment
c. both a. and b.
d. none of the above
 Answer  Explanation ANSWER: both a. and b. Explanation: No explanation is available for this question!

5)   What is the S.I. unit of torsional rigidity?

a. Nm
b. N.m2
d. None of the above
 Answer  Explanation ANSWER: N.m2 Explanation: No explanation is available for this question!

6)   In the relation ( T/J = Gθ/L = τ/ R), the letter G denotes modulus of  ______

a. elasticity
b. plasticity
c. rigidity
d. resilience
 Answer  Explanation ANSWER: rigidity Explanation: No explanation is available for this question!

7)   Which of the following relation represents torsional flexibility?

a. GJ
b. GL
c. GJ / L
d. L / GJ
 Answer  Explanation ANSWER: L / GJ Explanation: No explanation is available for this question!

8)   Stress in the cross section of a shaft at the centre ________

a. is zero
b. decreases linearly to the maximum value of at outer surface
c. both a. and b.
d. none of the above
 Answer  Explanation ANSWER: is zero Explanation: No explanation is available for this question!

9)   What is the maximum principle stress induced in a solid shaft of 40 mm diameter which is subjected to both bending moment and torque of 300 kN.mm and 150 kN.mm respectively?

a. 21.69 N/mm2
b. 28.1 N/mm2
c. 50.57 N/mm2
d. 52.32 N/mm2
 Answer  Explanation ANSWER: 50.57 N/mm2 Explanation: No explanation is available for this question!

10)   What is the maximum shear stress induced in a solid shaft of 50 mm diameter which is subjected to both bending moment and torque of 300 kN.mm and 200 kN.mm respectively?

a. 9.11 N/mm2
b. 14.69 N/mm2
c. 16.22 N/mm2
d. 20.98 N/mm2
 Answer  Explanation ANSWER: 14.69 N/mm2 Explanation: No explanation is available for this question!