Lecture Notes: Vernier Scale and Vernier Calipers

Introduction

• Objective: Understand the concept of the least count and the structure of vernier calipers.
• Components: Vernier calipers consist of two scales - the main scale and the vernier scale.
• Main Scale: Similar to a meter rule, calibrated in centimeters and millimeters.

Main Scale

• The main scale is graduated like a meter rule:
  • 1 centimeter is divided into 10 equal divisions.
  • Each division equals 1 millimeter (0.1 cm).
• Counting on the main scale:
  • Start from 0.1 cm, adding 0.1 cm repeatedly (e.g., 0.1, 0.2, 0.3, …, 1.0 cm).
  • The smallest division on the main scale is 0.1 cm.
• Least Count on Main Scale: 0.1 cm.

Vernier Scale

• Structure:
  • Starts from zero and has 10 divisions.
  • These 10 divisions span a total of 0.9 cm on the main scale.
• Division Calculation:
  • 0.9 cm divided by 10 equals 0.09 cm per division on the vernier scale.
• Comparison:
  • A division on the vernier scale (0.09 cm) is smaller than one on the main scale (0.1 cm).

Least Count of Vernier Calipers

• Calculation:
  • Difference between main scale and vernier scale division: 0.1 cm - 0.09 cm = 0.01 cm.
• Significance:
  • The least count determines the precision of measurement, allowing for 0.01 cm accuracy.
  • Vernier calipers enable reading to the second decimal place (0.01 cm) which is not possible with a regular meter rule.

Importance of Vernier Calipers

• Precision: Vernier calipers are more precise than a meter rule.
• Reading Values: Enables measurement to 0.01 cm versus the 0.1 cm accuracy of a meter rule.

Conclusion

• Recap:
  • Vernier calipers have two scales: main scale (0.1 cm least count) and vernier scale (0.01 cm least count).
  • Vernier scale helps achieve greater precision in measurements.
• Next Steps:
  • Review the content for understanding.
  • Future lessons will cover how to read the vernier scale.

Additional Information

• Online Classes: Video lessons for various educational stages are available.
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These notes cover the key points from the lesson on vernier scales and calipers, focusing on the understanding of the least count and precision of these measuring tools.