JEE Main 2021PhysicsExperimental PhysicsMediumMCQ

JEE Main 2021 — Experimental Physics Question with Solution

JEE Main 2021 (27 Jul Shift 1)

Question

Assertion A: If in five complete rotations of the circular scale, the distance travelled on the main scale of the screw gauge is 5 mm and there are 50 total divisions on a circular scale, then the least count is 0.001 cm.

Reason R:
Least Count = Pitch  Total divisions on circular scale 
In the light of the above statements, choose the most appropriate answer from the options given below.

Choose an option

Show full solutionCorrect option: A
Correct answer
AA is not correct but R is correct.

Step-by-step explanation

Least count = Pitch  total division on circular scale 
In 5 revolution, distance travel, 5 mm.

In 1 revolution, it will travel 1 mm.
So the least count =150=0.02

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About this question

This is a previous-year question from JEE Main 2021, 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.