Mechanics of Materials — Quiz 1

Questions in this quiz (10)

1. Determine the moment at the fixed end support of a cantilever beam subjected to a point load of 250 N at the free end with a beam length of 2.5 m.

   • 625 Nm (clockwise)
   • 625 Nm (counter clockwise)
   • 312.5 Nm (clockwise)
   • 312.5 Nm (counter clockwise)

2. A steel bar is stretched beyond its yield point causing permanent deformation. After unloading, the bar is loaded again. Which of the following statements is true?

   • The modulus of elasticity changes
   • The yield strength increases
   • The ductility decreases
   • The elastic limit decreases

3. Find the correct equation to define normal strain ε. Assume the symbol ΔL is elongation and L is the original length

   • ε = L / ΔL
   • ε = (L + ΔL) / L
   • ε = ΔL / L
   • ε = ΔL / (L + ΔL)

4. A steel rod is subjected to a tensile force of 300 N. The rod has a length of 50 m and diameter 2 mm. If the modulus of elasticity is $$2 × 10^5$$ MPa, determine the strain in the rod.

   • $$4.78 × 10^{-4}$$
   • $$6.37 × 10^{-4}$$
   • $$7.96 × 10^{-4}$$
   • $$9.12 × 10^{-4}$$

5. Determine the location of maximum deflection of a simply supported beam subjected to uniformly distributed load across entire span.

   • At the support
   • At 1/4 span
   • At midspan
   • At 3/4 span

6. Determine the maximum principal strain at a point where εx = 900 μm εy = -500 μm γxy = 700 μm

   • 745 μm
   • 945 μm
   • 1045 μm
   • 1245 μm

7. A tensile force of 150 kN is applied on a 0.025-m diameter and 2.5-m long rod. After applying the load, the diameter of the rod decreases to 0.02497 m and the length increases to 2.515 m. The engineering stress on the rod is most nearly:

   • 305 MPa
   • 318 MPa
   • 382 MPa
   • 412 MPa

8. A tensile force of 150 kN is applied on a 0.025-m diameter and 2.5-m long rod. After applying the load, the diameter of the rod decreases to 0.02497 m and the length increases to 2.515 m. The true stress on the rod is most nearly:

   • 307 MPa
   • 335 MPa
   • 382 MPa
   • 412 MPa

9. A tensile force of 120 kN is applied on a 0.025-m diameter and 2.5-m long rod. After applying the load, the length increases to 2.512 m. The engineering axial strain is most nearly:

   • 0.24%
   • 0.48%
   • 0.60%
   • 0.75%

10. A tensile force of 120 kN is applied on a 0.025-m diameter and 2.5-m long rod. After applying the load, the length increases to 2.512 m. The true axial strain is most nearly:

    • 0.24%
    • 0.48%
    • 0.60%
    • 0.75%