Quiz on Stress, Strain, and Thermal Expansion

What is the definition of stress?

• Ratio of the perpendicular force to the cross-sectional area

• The force applied per unit volume

• Ratio of change in length to the original length

• The total force acting on a body

What is the unit of strain?

• Pa

• Nm

• Dimensionless

• N/m²

What happens at the elastic limit?

• Material breaks

• Material returns to original length

• Material undergoes plastic deformation

• Material is permanently deformed

Which region indicates plastic deformation in a stress-strain graph?

• OA

• CDE

• OT

• OB

What is Young's Modulus a measure of?

• The ratio of tensile stress to tensile strain

• The maximum stress a material can withstand

• The total energy stored in a material

• The change in length per unit length

What is the formula for Young's Modulus?

• Y = ε/σ

• Y = σ/ε

• Y = ΔL/L0

• Y = F/A

What is the coefficient of linear expansion?

• Change in volume per unit volume

• Change in area per unit area

• Change in length per unit length

• Change in temperature per unit temperature

What is the effect of increasing temperature on the length of a steel measuring tape?

• It causes the tape to break

• It has no effect

• It increases the length

• It decreases the length

What is the energy stored in a wire related to?

• The temperature of the wire

• The strain in the wire

• The length of the wire

• The cross-sectional area of the wire

What happens to a brittle material under stress?

• It breaks without plastic deformation

• It bends easily

• It stretches significantly

• It shows significant plastic deformation