CourseCourseConceptConceptDocumentDocument

CAIE A-Level Physics AS 6.1 Stress and Strain Questions

Practise analysing springs and wires using force, extension, stress, strain and Young modulus, including Hooke’s law and experimental evaluation.

Syllabus
2028–2030
Course
Physics 9702
Level
AS

Exam points

  • identify tensile and compressive deformation and use load, extension, compression and limit-of-proportionality language with force–extension evidence
  • apply Hooke’s law and k = F/x to calculate force, extension, spring constant or equivalent spring behaviour
  • calculate stress, strain and Young modulus from force, area, extension and original length, interpreting graphs and units
  • describe and evaluate a Young-modulus experiment using appropriate measurements, apparatus, controls and repeated data

Covered syllabus points

6.1.1—Deformation is caused by tensile or compressive forces (forces and6.1.2—The terms load, extension, compression and limit of proportionality6.1.3—Hooke’s law6.1.4—The formula for the spring constant k = F / x6.1.5—The terms stress, strain and the Young modulus6.1.6—The Young modulus of a metal in the form of a wire

Question 1

[Maximum number: 1]

The diagram shows a beam supported on two pivots.

Figure for Question 1 — CAIE A-Level Physics AS

Which statement describes the state of the top surface X and of the bottom surface Y ?

A

Both X and Y are in compression.

B

Both X and Y are in tension.

C

X is in compression and Y is in tension.

D

X is in tension and Y is in compression.

Question 2

[Maximum number: 1]

A force-extension graph is produced for a metal wire.
What must describe the limit of proportionality of the wire?

A

the point at which the wire breaks

B

the point beyond which Hooke's law is not obeyed

C

the point beyond which the wire cannot return to its original length

D

the point beyond which the wire starts to deform plastically

Question 3

[Maximum number: 1]

A lamp is suspended in equilibrium from a fixed support by three long identical wires.

Figure for Question 3 — CAIE A-Level Physics AS

The weight of the lamp causes each wire to have an extension of 0.40 cm . The height h of the lamp above the floor is measured.

The middle wire suddenly breaks and the lamp falls a small distance as the extensions of the remaining two wires increase. The wires obey Hooke's law.

When the lamp is in equilibrium, the height h of the lamp above the floor is measured again.
What is the difference between the two values of h ?

A

0.20 cm0.20 \mathrm{~cm}

B

0.27 cm0.27 \mathrm{~cm}

C

0.40 cm0.40 \mathrm{~cm}

D

0.60 cm0.60 \mathrm{~cm}

Question 4

[Maximum number: 1]

An extension-force graph for a spring is shown.

Figure for Question 4 — CAIE A-Level Physics AS

What is the spring constant of the spring?

A

0.025Nm−10.025 \mathrm{Nm}^{-1}

B

0.40Nm−10.40 \mathrm{Nm}^{-1}

C

2.5Nm−12.5 \mathrm{Nm}^{-1}

D

40Nm−140 \mathrm{Nm}^{-1}

Question 5

[Maximum number: 1]

Two wires, one made of brass and the other of steel, are stretched in an experiment. Both wires obey Hooke's law during this experiment.

The Young modulus for brass is less than the Young modulus for steel.
Which graph shows how the stress varies with strain for both wires in this experiment?

A
Figure for Question 5 — CAIE A-Level Physics AS — Option A
B
Figure for Question 5 — CAIE A-Level Physics AS — Option B
C
Figure for Question 5 — CAIE A-Level Physics AS — Option C
D
Figure for Question 5 — CAIE A-Level Physics AS — Option D

Question 6

[Maximum number: 3]

A wire is fixed at one end so that it hangs vertically. The wire is given an extension x by suspending a load F from its free end. The variation of F with x is shown in Fig. 3.1.

Fig. 3.1

Fig. 3.1

The wire has cross-sectional area 9.4×10−8 m29.4 \times 10^{-8} \mathrm{~m}^{2} and original length 2.5 m .

Describe how measurements can be taken to determine accurately the cross-sectional area of the wire.

All question bank results loaded