JEE Main 2026 — Experimental Physics Question with Solution
JEE Main 2026 (28 January Shift 2)
Question
In an experiment, a set of reading are obtained as follows - , 1.21 mm. The expected least count of the instrument used in recording these readings is mm.
Choose an option
Show full solutionCorrect option: C
Correct answer
C0.01
Step-by-step explanation
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.
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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This is a previous-year question from JEE Main 2026, covering the Experimental Physics chapter of Physics. PrepSharp catalogues every PYQ from JEE Main with a verified answer key and step-by-step solution prepared by IIT alumni — so you can search by chapter, topic or year and revise efficiently.