Question

A screw gauge has pitch 1 mm and 100 circular divisions. Zero error = 8 divisions below. With a wire, 1st main scale is visible and 72nd circular division coincides. Find the wire’s radius.

पर्याय

• 1.64 mm

• 0.82 mm

• 1.80 mm

• 0.90 mm

Answer 1

0.82 mm

Explanation:

Least count = \[\frac {\text {1 mm}}{100}\] = 0.01 mm

Zero error = +8 × L.C = +0.08 mm

True reading (diameter) = (1 mm + 72 × 0.01 mm) - 0.08 mm

= 1.72 mm - 0.08 mm = 1.64 mm

Therefore, radius = \[\frac{\text{diameter}}{2}\] = \[\frac {1.64}{2}\] = 0.82 mm