# Strength of Materials 11

Mechanical Engineering MCQ Question Papers: DRDO, ISRO, Interview

Subject: Strength of Materials 11

Part 5: List for questions and answers of Strength of Materials

Q1. A tensile test is performed on a mild steel round bar. Its diameter after fracture will
a) Remain same
b) Increase
c) Decrease

Q2. A shaft is said to be in pure torsion if
a) Turning moment is applied at one end and other end is free
b) Turning force is applied at one end and other end is free
c) Two opposite turning moments are applied to the shaft
d) Combination of torsional load and bending load is applied to the shaft

Q3. In power transmission equation, , P=2ΠNT/60×1000
a) P is in kw and T is maximum torque
b) P is in NM/sec and T is maximum torque
c) P is in NM/sec and T is mean torque
d) P is in kw and T is mean torque

Q4. Which property is not required for shaft materials?
a) High shear and tensile strength
b) Good machinability
c) High fatigue strength
d) Good castability

Q5. Which material is suitable for shaft material?
a) High speed steel
b) Stainless steel or high carbon steel
c) Grey cast iron
d) Steel having approx. 0.4% carbon and 0.8% manganese

Q6. If diameter of a shaft is doubled the power transmitted capacity will be
a) Either twice or half
b) Four times
c) Eight times
d) Same

Q7. Two shafts in torsion will have equal strength if
a) Only diameter of the shafts is same
b) Only angle of twist of the shaft is same
c) Only material of the shaft is same
d) Only torque transmitting capacity of the shaft is same

Q8. Which of the following is not designed under torsion equation?
a) Spindle
b) Axle
c) Low cost shaft
d) Shaft with variable diameter

Q9. Which of the following is incorrect?
a) In torsion equation, we use mean torque
b) In torsion equation, we use maximum torque
c) Many shafts are designed under combined bending and torsion load
d) Shafts are also designed for torsional rigidity

Q10. Which of the following is incorrect?
a) In a solid shaft maximum shear stress occurs at radius = radius of shaft
b) In a solid shaft maximum shear stress occurs at center
c) In a hollow shaft maximum shear stress occurs at outer radius
d) In a hollow shaft minimum shear stress occurs at inner radius

Q11. The following option is correct
a) There is neither advantage nor disadvantage in transmitting power at high speed
b) There is advantage in transmitting power at high speeds
c) There is disadvantage in transmitting power at high speeds
d) There is advantage in transmitting power at high speed provided shafts are made of high speed steel

Q12. Torsional rigidity is defined as
a) T/ θ ¸
b) C θ ¸
c) Cip
d) Θ

Q13. Which of the following is not an assumption in derivation of torsion equation?
a) Circular shaft remains circular after twisting
b) Plane section of the shaft remain plane after twisting
c) Material of shaft is isotropic
d) Angle of twist is proportional to radius

Q14. Strength of a shaft
a) Is equal to maximum shear stress in the shaft at the time of elastic failure
b) Is equal to maximum shear stress in the shaft at the time of rupture
c) Is equal to torsional rigidity
d) Is ability to resist maximum twisting moment

Q15. St. Venant’s theory is also known as maximum _________
a) Principle stress theory
b) Shear stress theory
c) Principle strain theory
d) Strain energy theory

Q16. According to Coulomb’s theory, material subjected to complex stresses fails, if_______ shear stress induced in the material exceeds _______ shear stress at the yield
point
a) Minimum, maximum
b) Maximum, minimum
c) Maximum, maximum
d) Minimum, minimum

Q17. Which theory gives satisfactory results for brittle materials?
a) Maximum shear stress theory
b) Maximum principle stress theory
c) Shear strain energy theory
d) None of the above

Q18. For designing ductile materials, which of the following theories is/are used?
a) Maximum shear stress theory
b) Shear strain energy theory
c) Both a. And b.
d) None of the above

Q19. Shear stress energy theory is called as ______
a) Distortion theory
b) Von Mises theory
c) Both a. And b.
d) None of the above

Q20. 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

Part 5: List for questions and answers of Strength of Materials

Q6.