Objective Questions and Answer: Mechanics & Strength of Materials 15

Subject: Mechanics & Strength of Materials 15

**Part 15: Objective questions and answers of Mechanics & Strength Of Materials**

**Q1. A beam of triangular section is placed with its base horizontal. The maximum shear stress occurs at**

a) Apex of the triangle

b) Mid of the height

c) Centre of gravity of the triangle

d) Base of the triangle

**Q2. Which of the following statement is wrong?**

a) In the theory of simple bending, the assumption is that the plane sections before bending remains plane after bending

b) In a beam subjected to bending moment, the strain is directly proportional to the distance from the neutral axis.

c) At the neutral axis of a beam, the bending stress is maximum.

d) The bending stress in a beam is inversely proportional to the section modulus.

**Q3. A flitched beam is used to**

a) Change he shape of the beam

b) Effect the saving in material

c) Equalize the strength in tension and compression

d) Increase the cross-section of the beam

**Q4. A cantilever beam of length l carries a gradually varying load from zero at free end and w per unit length at the fixed end. The maximum deflection lies at**

a) Free end

b) Fixed end

c) Mid-span

d) Free end

**Q5. The product of Young's modulus and moment of inertia is given as**

a) Modulus of rigidity

b) Bulk modulus

c) Flexural rigidity

d) Torsional rigidity

**Q6. The product of the tangential force acting on the shaft and its distance from the axis of the shaft is known as**

a) Bending moment

b) Twisting moment

c) Torsional rigidity

d) Flexural rigidity

**Q7. When a shaft is subjected to a twisting moment, every cross-section of the shaft will be under**

a) Tensile stress

b) Compressive stress

c) Shear stress

d) Bending stress

**Q8. The shear stress at the centre of a circular shaft is under torsion is**

a) Zero

b) Minimum

c) Maximum

d) Infinity

**Q9. The shear stress at the outermost fibers of a circular shaft under torsion is**

a) Zero

b) Minimum

c) Maximum

d) Infinity

**Q10. When a shaft is subjected to torsion, the shear stress is induced in the shaft varies from**

a) Minimum at the centre to maximum at the circumference

b) Maximum at the centre to minimum at the circumference

c) Zero at the centre to maximum at the circumference

d) Maximum at the centre to zero at the circumference

**Q11. For a shaft, the shear stress at a point is ______ the distance from the axis of the shaft.**

a) Equal to

b) Directly proportional to

c) Inversely proportional to

d) None of the above

**Q12. When two shafts of same length, one of which is hollow, transmit equal torques and have equal maximum stress, then they should have equal**

a) Polar moment of inertia

b) Polar modulus

c) Diameter

d) Angle of twist

**Q13. In spring balances, the spring is used**

a) To apply forces

b) To measure forces

c) To absorb shocks

d) To store strain energy

**Q14. The springs in brakes and clutches are used to**

a) To apply forces

b) To measure forces

c) To store strain energy

d) To absorb shocks

**Q15. In a watch, the spring is used to store strain energy. This energy is released**

a) To stop the watch

b) To run the watch

c) To change the time

d) All of these

**Q16. A spring used to absorb shocks and vibrations is**

a) Conical spring

b) Torsion spring

c) Leaf spring

d) Disc spring

**Q17. The load required to produce a unit deflection in a spring is called**

a) Flexural rigidity

b) Torsional spring

c) Spring stiffness

d) Young's modulus

**Q18. A leaf spring is supported at the**

a) Ends and loaded at the centre

b) Centre and loaded at the ends

c) Ends and loaded anywhere

d) Centre and loaded anywhere

**Q19. When a closely-coiled helical spring is subjected to an axial load, it is said to be under**

a) Bending

b) Shear

c) Torsion

d) Crushing

**Q20. A closely-coiled helical spring is cut into two halves. The stiffness of the resulting spring will be**

a) Same

b) Double

c) Half

d) One-fourth

**Part 15: Objective questions and answers of Mechanics & Strength Of Materials**

Q1. Answer b

Q2. Answer c

Q3. Answer c

Q4. Answer

Q5. Answer c

Q6. Answer b

Q7. Answer c

Q8. Answer a

Q9. Answer c

Q10. Answer c

Q11. Answer b

Q12. Answer b

Q13. Answer b

Q14. Answer a

Q15. Answer b

Q16. Answer c

Q17. Answer c

Q18. Answer b

Q19. Answer c

Q20. Answer b