JEE Main 2024 — Experimental Physics Question with Solution
JEE Main 2024 (06 Apr Shift 2)
Question
In a vernier calliper, when both jaws touch each other, zero of the vernier scale shifts towards left and its division coincides exactly with a certain division on main scale. If 50 vernier scale divisions equal to 49 main scale divisions and zero error in the instrument is then how many main scale divisions are there in ?
Choose an option
Show full solutionCorrect option: C
Correct answer
C20
Step-by-step explanation
$\begin{aligned}
& 50 \mathrm{VSD}=49 \mathrm{MSD} \\
& 1 \mathrm{VSD}=\frac{49}{50} \mathrm{MSD} \\
& \mathrm{LC}=1 \mathrm{MSD}-1 \mathrm{VSD} \\
& \mathrm{LC}=1 \mathrm{MSD} \cdot \frac{49}{50} \mathrm{MSD}=\frac{\mathrm{MSD}}{50} \ldots . . . . . .(1) \\
& \text {Now, } | \text { zero error }|=| 0-4(\mathrm{~L} . \mathrm{C}) | \\
& 0.04=|-4(\mathrm{~L} . \mathrm{C})| \Rightarrow \mathrm{L} . \mathrm{C}=0.01 \mathrm{~mm} \\
& \mathrm{0 . 0 4}=|-\mathrm{4}(\mathrm{L} . \mathrm{C})| \Rightarrow \mathrm{L} . \mathrm{C} \ldots . . .(2) \\
& =\mathrm{0 . 0 1} \mathrm{mm}
\end{aligned}$
Using (1) and (2)
$\begin{aligned}
& \frac{M S D}{50}=0.01 \\
& M S D=0.5 \mathrm{~mm} \\
& M S D=\frac{1 \mathrm{~cm}}{\mathrm{~N}} \\
& \mathrm{~N}=\frac{1 \mathrm{~cm}}{0.5 \mathrm{~mm}}=\frac{100 \mathrm{~mm}}{5 \mathrm{~mm}} \\
& \mathrm{~N}=20
\end{aligned}$
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This is a previous-year question from JEE Main 2024, 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.