🌈 Vernier Callipers Mind Map for Class 9 – Easy & Visual Learning Tool

Rainbow Mind Map: Vernier Callipers

1. Definition

A Vernier Callipers is a measuring instrument used to measure the length, diameter, and depth of small objects accurately (up to 0.01 cm).

2. Main Parts

• Fixed Jaw
• Sliding Jaw
• Main Scale
• Vernier Scale
• Locking Screw
• Depth Rod

3. Least Count

• Smallest measurement it can take
• Usually 0.1 mm or 0.01 cm
• Least Count = 1 MSD – 1 VSD

4. Uses

• Measure internal diameter (e.g., of a test tube)
• Measure external diameter (e.g., of a wire)
• Measure depth (e.g., of a beaker)

5. How to Read

1. Take main scale reading (MSR)
2. Find the vernier scale division that coincides (VSR)
3. Use formula: Total reading = MSR + (VSR × LC)

6. Zero Error

• When jaws are closed, reading ≠ 0
• Types: Positive, Negative, or Zero
• Must be added or subtracted from the final reading

7. Care & Accuracy

• Keep jaws clean and aligned
• Do not drop or force the scale
• Use locking screw for fixed readings

Let’s Test Your Knowledge!
Can you explain the steps to find the diameter of a marble using a Vernier Callipers?

Post your answer in the comments below – let's inspire others to measure with precision!

Check out this video on YouTube