Instructions

  1. Measure the wire diameter: Examine the three micrometer images below. Each shows a different measurement of the wire diameter. Record all three readings.
  2. Calculate average diameter: Find the average of your three measurements.
  3. Add masses: Use the apparatus below to add masses (1kg increments) and observe the wire extension.
  4. Measure extension: Read the vernier scale extension for each added mass.
  5. Record data: Write all your measurements in the data table on paper.
  6. Calculate Young's Modulus: Use the formula: E = (F × L) / (A × ΔL)
  7. Draw a graph: Plot Load (N) vs Extension (mm) on graph paper.

Formula

E = (F × L) / (A × ΔL)
  • E = Young's Modulus (Pa)
  • F = Force applied (N) = m × g
  • L = Original length of wire (m)
  • A = Cross-sectional area (m²) = πr²
  • ΔL = Extension (m)

Step 1: Measure Wire Diameter (Micrometer)

Examine the three micrometer images below. Record all three diameter readings in the spaces provided.

Reading 1

Micrometer Reading 1

Reading 2

Micrometer Reading 2

Reading 3

Micrometer Reading 3

Diameter Summary

-

Step 2: Apparatus Setup

Step 3: Conduct Experiment

Searle's Apparatus

Rigid Support Beam Control Wire Scale Test Wire Vernier 0g ← Wire Length L → Extension ΔL

Vernier Scale (Interactive)

Read the vernier scale carefully. The main scale shows mm, and the vernier scale shows 0.1 mm divisions.

Main Scale (mm) Vernier Scale (0.1 mm) Reading: 0.0 mm

Add Masses (1kg each)

Current Load: 0 × 1kg = 0g

Measure Extension (Vernier Scale)

Read the vernier scale and record the extension below.

Data Collected

Mass Added (g) Force (N) Extension (mm) Status

Summary of Collected Data

Mass (g) Force (N) Extension (mm) Remove

No data collected yet.

Next Steps

📊 Plot Your Graph

  1. On graph paper, draw a graph of Load (N) vs Extension (mm)
  2. Plot your data points from the table above
  3. Draw a best-fit line through your points
  4. Calculate the gradient: Gradient = ΔLoad / ΔExtension

📐 Calculate Young's Modulus

Use the formula:

E = (Gradient × L) / A

Where:

  • Gradient = slope from your graph (N/mm)
  • L = wire length (m) = 1.0 m
  • A = cross-sectional area (m²) = π × r²

📝 Show Your Working

Wire diameter (average): - mm

Wire radius: - m

Cross-sectional area: - m²

To find Young's Modulus from your graph:

E = (Gradient × L) / A

E = (your gradient × 1.0) / your area

E = Your answer in Pa