Least Count, Vernier Callipers & Screw Gauge
In an experiment, a set of readings are obtained as follows: 1.24 mm, 1.25 mm, 1.23 mm, 1.21 mm. The expected least count of the instrument used in recording these readings is _______ mm.
Show answer and solution
Answer: (a)
- The last significant digit of each reading is in the 0.01 mm place.
- Readings differ in steps of 0.01 mm, so the instrument reads to 0.01 mm.
- So the least count is (a) mm.