1. What type of loading does pure bending involve?
a) Torsional loading
b) Axial loading
c) Shear loading
d) Bending loading
Answer: d) Bending loading
Explanation: Pure bending involves the application of bending moments to a structural member without any axial or torsional loads. It leads to deformation characterized by curvature along the axis of the member.
2. In symmetric members under pure bending, where is the neutral axis located?
a) At the centroid of the section
b) At the top surface of the section
c) At the bottom surface of the section
d) At the extreme fibers of the section
Answer: a) At the centroid of the section
Explanation: In symmetric members under pure bending, the neutral axis is located at the centroid of the cross-sectional area. It’s the axis where the stress is zero during bending.
3. What is the primary cause of deformation in a beam under bending?
a) Shear stress
b) Axial stress
c) Tensile stress
d) Bending stress
Answer: d) Bending stress
Explanation: Bending stress is the primary cause of deformation in a beam under bending. It results from the moment applied to the beam, causing it to bend and inducing stress throughout its cross-section.
4. When a composite section is subjected to bending, what property governs the distribution of stresses?
a) Material density
b) Modulus of elasticity
c) Cross-sectional area
d) Poisson’s ratio
Answer: b) Modulus of elasticity
Explanation: The modulus of elasticity of the constituent materials governs the distribution of stresses in a composite section subjected to bending. Materials with different moduli of elasticity will experience different levels of stress.
5. In eccentric axial loading, the applied load does not pass through the centroid of the section, resulting in what kind of stress?
a) Bending stress
b) Shear stress
c) Torsional stress
d) Axial stress
Answer: a) Bending stress
Explanation: In eccentric axial loading, the applied load does not pass through the centroid of the section, leading to bending moments and hence bending stress in addition to axial stress.
6. What is the graphical representation of shear force along the length of a beam called?
a) Stress diagram
b) Moment diagram
c) Shear force diagram
d) Bending moment diagram
Answer: c) Shear force diagram
Explanation: A shear force diagram illustrates the variation of shear force along the length of a beam. It shows the magnitude and direction of the internal shear forces at different points along the beam.
7. According to the relationship between load, shear, and bending moment, what is the derivative of shear force with respect to the x-coordinate?
a) Load
b) Bending moment
c) Shear stress
d) Slope of the beam
Answer: a) Load
Explanation: The derivative of shear force with respect to the x-coordinate gives the rate of change of load along the beam’s length. This relationship is fundamental in analyzing beam behavior.
8. What type of stress arises in beams due to the internal shear forces?
a) Tensile stress
b) Compressive stress
c) Bending stress
d) Shear stress
Answer: d) Shear stress
Explanation: Internal shear forces in beams lead to shear stress, which acts parallel to the cross-section and contributes to the beam’s deformation and failure.
9. What type of energy is stored in a beam subjected to bending?
a) Kinetic energy
b) Potential energy
c) Strain energy
d) Thermal energy
Answer: c) Strain energy
Explanation: Strain energy is stored in a beam subjected to bending due to the deformation caused by bending stresses. It represents the energy absorbed by the material when it deforms elastically.
10. Which method is used to determine the deflection of beams by integrating the equation of the elastic curve?
a) Macaulay’s method
b) Area moment method
c) Finite element method
d) Method of joints
Answer: a) Macaulay’s method
Explanation: Macaulay’s method is a mathematical technique used to determine the deflection of beams by integrating the equation of the elastic curve. It’s particularly useful for solving complex loading and support conditions.