A screw gauge gives the following readings when used to measure the diameter of a wire. Main scale reading : 0 mm. Circular scale reading : 52 divisions. Given that 1 mm on main scale corresponds to 100 divisions on the circular scale. The diameter of the wire from the above data is:

A 0.026 cm

B 0.26 cm

C 0.052 cm

D 0.52 cm

The answer is C.

Solution

Least count $= \frac{1\ mm}{100} = 0.01$ mm Diameter = main scale reading + circular scale reading × LC $= 0 + 52 \times 0.01 = 0.52$ mm $= 0.052$ cm

Concept screw gauge reading

2 questions from this chapter have appeared across 2 exam years.