This lesson includes 7 additional questions for subscribers.

# Lesson Worksheet: Deformation due to Strain Physics

In this worksheet, we will practice describing how stresses applied to objects result in variations in strain that correspond to deformations.

**Q1: **

The graph shows how the tensile strain on a wire varies with the tensile stress on it. Between points I and III and between points IV and V, the graph has a decreasing gradient. The change in the tensile strain on the wire between two points on the graph is , and the change in the tensile stress on the wire between two points is . Which of the following describes correctly what would happen to the wire between these points, in the direction of increased strain?

- AThe ratio of to would decrease.
- BThe tensile force would remain constant.
- CThe ratio of to would increase.
- DThe tensile force would decrease.
- EThe ratio of to would be constant.

**Q2: **

The graph shows how the tensile strain on a wire varies with the tensile stress on it. Where on the graph does the Young’s modulus of the wire have a constant value?

- AThroughout the whole graph
- BAt point I
- CNowhere on the graph
- DBetween the origin and point I
- EAt points III and V

**Q3: **

The graph shows how the tensile strain on a wire varies with the tensile stress on it. Where on the graph is the Young modulus of the wire increasing?

- ANowhere on the graph
- BOnly between the origin and point I
- COnly between the origin and point III
- DEverywhere except between points III and IV and between points V and VI
- EThroughout the graph

**Q4: **

The graph shows how the tensile strain on a wire varies with the tensile stress on it. Which point on the graph corresponds to the ultimate tensile strength of the wire?

- AV
- BIII
- CIV
- DI
- EVI

**Q5: **

The graph shows how the tensile strain on wires of identical shape and size made of substance I and substance II vary with the tensile stress on them.

Which substance produces a wire that can support a greater weight without breaking?

- ASubstance II
- BSubstance I

Which substance produces a wire that can extend further without breaking?

- ASubstance II
- BSubstance I

**Q6: **

The graph shows how the tensile strain on a wire varies with the tensile stress on it. For strain values less than those corresponding to point II, the wire will return to its original length when the stress on it is reduced to zero. The wire deforms negligibly in any direction other than the direction of the tensile force on it for values of strain less than those that correspond to point V. Which of the following most correctly explains why the Young’s modulus of the wire changes between points I and II?

- AThe cross-sectional area of the wire increases, increasing the tensile stress on the wire per newton of tensile force on it.
- BThe cross-sectional area of the wire decreases, increasing the tensile stress on the wire per newton of tensile force on it.
- CThe bonds between the atoms in the wire break and different bonds form.
- DThe cross-sectional area of the wire increases, decreasing the tensile stress on the wire per newton of tensile force on it.
- EThe average force of attraction between atoms in the wire decreases, but no bonds between the atoms break or form.

**Q7: **

The graph shows the change in the extension of a rubber band as the weight it supports is increased from zero and then decreased to zero.

Does the red line or the blue line represent increasing the supported weight?

- ABlue
- BRed

The graph is divided into six regions. Each region is bounded by either the blue line or the red line and by one of the grey dashed line nearest to either line. Which combination of regions has a total area equivalent to the energy dissipated during the increasing and decreasing of the supported weight?

- AV and VI
- BII, IV, V, and VI
- CI and II
- DIII and IV
- EI, III, and V

**Q8: **

Which of the following correctly describes what the toughness of a wire depends on?

- AThe toughness of a wire depends on the ratio of the tensile force exerted on a wire to its extension in the direction of the force.
- BThe toughness of a wire depends on the tensile force that can be exerted on a wire that does not produce permanent extension.
- CThe toughness of a wire depends on the maximum extension by plastic deformation of a wire before the wire breaks.

**Q9: **

Which of the following correctly describes what the strength of a wire depends on?

- AThe strength of a wire depends on the tensile force that can be exerted on a wire that does not produce permanent extension.
- BThe strength of a wire depends on the maximum extension by plastic deformation of a wire before the wire breaks.
- CThe strength of a wire depends on the ratio of the tensile force exerted on a wire to its extension in the direction of the force.

**Q10: **

The graph shows how the tensile strain on a wire varies with the tensile stress on it. The diagram shows the shape of a section of the wire before and after the tensile strain on the wire exceeds a value that corresponds to one of the points on the diagram. Which point does correspond to?

- AIII
- BIV
- CI
- DV
- EVI