Strength of materials Test 1

A cylindrical rod of cross-sectional area A experienced pressure p due to a compressive force F. If the force applied is reduced to one-third what happens to pressure?

• also reduced to one-third

• tripled

• remains the same

What relationship exists between applied force and strain?

• direct

• indirect

• none at all

This refers to the ratio of tensile stress to tensile strain.

• Bulk Modulus of elasticity

• Shear Modulus of Rigidity

• Young's Modulus of elasticity

Given the Young's modulus of elasticity below rank the metals according to the magnitude of tensile stress it can hold from highest to lowest.

Aluminum 69 GPa

Brass 125 GPa

Steel 200 GPa

• Aluminum, Brass, Steel

• Brass, Aluminum, Steel

• Steel, Brass, Aluminum

What is the correct label for A and B shown in the figure below?

• A - Tension; B- Compression

• A - Compression; B - Tension

• A - Torsion; B - Tension

The bulk modulus of three materials are listed below. Arrange them from highest to lowest compressibility.

A : 2 x 10¹⁰ N/m²

B : 4 x 10¹⁰ N/m²

C : 10 x 10¹⁰ N/m²

• A, B, C

• B, C, A

• C, B, A

Compressibility is the inverse of bulk modulus.

• True

• False

How much force is required to shear off a metal sheet whose thickness is 2mm and width of 40cm? The shear stress is 5 x 10⁷ N/m².

• 400 kN

• 40 kN

• 4 kN

A 5cm cube of substance has its upperface displaced by 0.65cm by a tangential force of 0.25N. Calculate the modulus of rigidity.

• 769 Pa

• 7.69 Kpa

• 769 MPa

A nylon string, has a diameter of 2mm, is pulled by a force of 100N. Determine the stress.

• 315 MPa

• 31.5 MPa

• 3.15 MPa