Revision Numericals on Vernier callipers

Vernier Callipers

🔍 Vernier Calipers

📘 Important Concepts

1. Main Scale Reading (MSR): The reading on the main scale just before zero of vernier.

2. Vernier Scale Reading (VSR): Coinciding division × least count.

3. Least Count (LC): Smallest measurement = 1 MSD – 1 VSD = 0.01 cm

4. Observed Reading: MSR + VSR

5. Corrected Reading:

• Positive error → Subtract
• Negative error → Add

Formula: Final Reading = MSR + (VSC × LC) ± Zero Correction

🧩 Puzzles

1. If 10 VSD = 9 MSD, find the least count.

LC = 0.1 – 0.09 = 0.01 cm

2. MSR = 2.2 cm, VSC = 4 divisions. Find reading.

Reading = 2.2 + (4 × 0.01) = 2.24 cm

3. Observed reading = 2.24 cm, zero error = +0.03 cm. Find corrected reading.

Corrected = 2.24 – 0.03 = 2.21 cm

4. Observed reading = 3.10 cm, zero error = –0.06 cm. Find corrected reading.

Corrected = 3.10 + 0.06 = 3.16 cm

5. MSR = 5.6 cm, VSC = 7 divisions. Find reading.

Reading = 5.6 + (7 × 0.01) = 5.67 cm

6. If LC = 0.01 cm and 8th division coincides, find VSR.

VSR = 8 × 0.01 = 0.08 cm

7. Why is Vernier calipers more accurate than a ruler?

Because its least count is smaller (0.01 cm).

8. If there is no zero error, what is corrected reading?

Corrected = Observed reading

9. MSR = 1.5 cm, VSC = 3 divisions. Find reading.

Reading = 1.5 + (3 × 0.01) = 1.53 cm

10. What happens if zero error is ignored?

Measurement becomes incorrect.