# Principal Stresses and Strains - Mechanical Engineering (MCQ) questions and answers

1)   Which of the following formulae is used to calculate tangential stress, when a member is subjected to stress in mutually perpendicular axis and accompanied by a shear stress?

a. [(σx – σy)/2 ]sin θ – τ cos 2θ
b. [(σx – σy)/2 ]– τ cos 2θ
c. [(σx – σy)/2 ]sin θ – τ2 cos θ
d. None of the above
 Answer  Explanation ANSWER: [(σx – σy)/2 ]sin θ – τ cos 2θ Explanation: No explanation is available for this question!

2)   When a component is subjected to axial stress the normal stress σn is maximum, if cos θ is _______ . (σnxCos2θ)

1. maximum
2. minimum
3. always one
4. always zero

a. 1 and 4
b. 1 and 3
c. 2 and 3
d. 2 and 4
 Answer  Explanation ANSWER: 1 and 3 Explanation: No explanation is available for this question!

3)   The angle between normal stress and tangential stress is known as angle of  ______

a. declination
b. orientation
c. obliquity
d. rotation
 Answer  Explanation ANSWER: obliquity Explanation: No explanation is available for this question!

4)   Principal stress is the magnitude of ________ stress acting on the principal plane.

a. Normal stress
b. Shear stress
c. Both a. and b.
d. None of the above
 Answer  Explanation ANSWER: Normal stress Explanation: No explanation is available for this question!

5)   Which of the following stresses can be determined using Mohr's circle method?

a. Torsional stress
b. Bending stress
c. Principal stress
d. All of the above
 Answer  Explanation ANSWER: Principal stress Explanation: No explanation is available for this question!

6)   The graphical method of Mohr's circle represents shear stress (τ) on ______

a. X-axis
b. Y-axis
c. Z-axis
d. None of the above
 Answer  Explanation ANSWER: Y-axis Explanation: No explanation is available for this question!

7)   In Mohr's circle method, compressive direct stress is represented on ____

a. positive x-axis
b. positive y-axis
c. negative x-axis
d. negative y-axis
 Answer  Explanation ANSWER: negative x-axis Explanation: No explanation is available for this question!

8)   What is the value of shear stress acting on a plane of circular bar which is subjected to axial tensile load of 100 kN? (Diameter of bar = 40 mm , θ = 42.3o)

a. 58.73 Mpa
b. 40.23 Mpa
c. 39.60 Mpa
d. Insufficient data
 Answer  Explanation ANSWER: 39.60 Mpa Explanation: No explanation is available for this question!

9)   The maximum tangential stress σt = (σx sin 2θ)/2 is maximum if, θ is equal to ________

a. 45o
b. 90o
c. 270o
d. all of the above
 Answer  Explanation ANSWER: 45o Explanation: No explanation is available for this question!

10)   Minor principal stress has minimum ________

a. value of shear stress acting on the plane
b. intensity of direct stress
c. both a. and b.
d. none of the above
 Answer  Explanation ANSWER: intensity of direct stress Explanation: No explanation is available for this question!