Question

In a vernier calipers having 10 VSD, the vernier constant is 0.1 mm. When the jaws are closed, zero of vernier lies to the left of zero of mainand $7^{th}$ Vsd coincides with a main scale division. When a cylinder is placed between the jaws the main scale reading was 7.7 cm and vernier scale read 8 divisions. What is the diameter of the cylinder ?

• A. 77.5 mm
• B. 77.8 mm
• C. 78.5 mm
• D. 78.1 mm

Answer 1

The correct option is D 78.1 mm

Zero error = -0.3 mm
Reading = 77.8 mm
Diameter of cylinder = 77.8-(0.3) = 78.1 mm.