EIT - Engineer In Training Mechanics of Materials Questions and Answers

Question 1

A solid circular steel shaft with a diameter of 50 mm is subjected to a pure torque of 2.5 kNm. What is the maximum shear stress in the shaft?

Accepted Answer

101.9 MPa

Answer

50.9 MPa

Answer

25.5 MPa

Answer

203.7 MPa

Question 2

A 2-meter-long aluminum rod (E = 70 GPa) has a circular cross-section with a diameter of 20 mm. If a tensile load of 30 kN is applied axially, what is the resulting elongation of the rod?

Accepted Answer

2.73 mm

Answer

0.68 mm

Answer

1.36 mm

Answer

5.46 mm

Question 3

A cantilever beam of length L has a point load P applied at its free end, resulting in a maximum deflection δ. If the length of the beam is doubled to 2L while the load P and cross-sectional properties (E, I) remain constant, what is the new maximum deflection?

Accepted Answer

8δ

Answer

2δ

Answer

4δ

Answer

16δ

Question 4

Which of the following statements best describes the shear and moment diagrams for a simply supported beam subjected to a single concentrated counter-clockwise moment at its mid-span?

Accepted Answer

The shear diagram is a horizontal line (constant non-zero value), and the moment diagram consists of two sloped lines with an abrupt vertical jump at mid-span.

Answer

The shear diagram is triangular, and the moment diagram is parabolic.

Answer

The shear diagram is zero along the entire beam, and the moment diagram is rectangular.

Answer

The shear diagram has a vertical drop at mid-span, and the moment diagram is triangular.

Question 5

A point on a structural element is subjected to a state of plane stress with the following components: σ_x = 80 MPa, σ_y = -40 MPa, and τ_xy = 30 MPa. What is the maximum principal stress (σ_1) at this point?

Accepted Answer

87.1 MPa

Answer

20.0 MPa

Answer

67.1 MPa

Answer

-47.1 MPa

Question 6

A 5-meter-long steel column (E = 200 GPa) with a moment of inertia of 2.53 x 10^6 mm^4 is pinned at both ends. What is the approximate critical buckling load for this column?

Accepted Answer

200 kN

Answer

50 kN

Answer

800 kN

Answer

100 kN