NPTEL Week - 01

As per the lecture what are the modern outlook factor influencing the choice of material?

• Cost-effectiveness

• Aesthetics

• Environmental concerns

• Type of application

State true or false: Coefficient of variation is less for the knot free timber than concrete?

• True

• False

Wood is good in which of the loading:

• Flexural and compression

• Tensile and flexural

• Tensile and compression

• Flexural but not the compression

Typical uniaxial stress-strain diagrams for some engineering materials are shown below

• A is showing brittle nature of failure

• B is showing stress- strain graph of steel

• E is plastic material

• C and D are not having well defined yield point

The stress-strain behavior of three different materials A, B, and C are shown below in figure. Which among the following is/are true regarding the properties of these materials?

• A has higher stiffness compared to B and C

• C is a plastic material

• A has higher modulus compared to B and C

• B is the most ductile material amongst A, B, and C

Which of the following is the correct decreasing order of density?

• Diamond > Structural steel > Concrete > Epoxy resin

• Structural steel > Concrete > Epoxy resin Diamond

• Structural steel > Diamond > Concrete > Epoxy resin

• Diamond > Structural steel > Epoxy resin > Concrete

State true or false: Clay-Brick work is good in tension but not in compression?

• True

• False

Which material property is crucial when choosing a material based on both stiffness and strength criteria?

• Modulus of elasticity

• Density

• Toughness

• strength

In a bridge construction, assume all the piers are built using M45 grade concrete. What would have been the target compressive strength for the concrete, considering 50% failure is acceptable? (assume standard deviation as 7.5 MPa)

• 45 MPa

• 45 MPa

Match the pairs listed in column 1 with their corresponding level of information listed in column 2:

• 1-i, 2-ii, 3-iii

• 1-iii, 2-ii, 3-i

• 1-iii, 2-ii, 3-i

• 1-i & ii, 2-ii, 3-iii