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JEE Main 202628 JanuaryEvening Shift
Exam
JEE Main
Year
2026
Date
28 January
Shift
Evening Shift
Subject
Physics
Chapter
Experimental Physics

JEE Main 2026 · 28 January · Evening Shift · Physics · Experimental Physics

In an experiment, a set of reading are obtained as follows - 1.24...

In an experiment, a set of reading are obtained as follows - 1.24 mm,1.25 mm,1.23 mm1.24 \mathrm{~mm}, 1.25 \mathrm{~mm}, 1.23 \mathrm{~mm}, 1.21 mm. The expected least count of the instrument used in recording these readings is ____\_\_\_\_ mm.

Options

  1. A0.001
  2. B0.1
  3. C0.01
  4. D0.05

Correct answer

C. 0.01

Step-by-step solution

Least count is the smallest division readable on an instrument scale.
Given readings are 1.24 mm, 1.25 mm, 1.23 mm, 1.21 mm, all expressed to two decimal places.
The precision of measurement shows differences as small as 0.01 mm (e.g., 1.25 - 1.24 = 0.01 mm).
This indicates all readings can be recorded to the nearest 0.01 mm, which represents the smallest measurable division.
Therefore, the least count of the instrument is 0.01 mm.
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