JEE Main 2013 — Units and Dimensions Question with Solution
JEE Main 2013 (09 Apr Online)
Question
From the following, the quantity (constructed from the basic constants of nature), that has the dimensions, as well as correct order of magnitude, vis-a-vis typical atomic size, is:
Choose an option
Show full solutionCorrect option: A
Correct answer
A
Step-by-step explanation
As
also
Therefore dimensionally
$\begin{aligned}
& \mathrm{mc}^2=\frac{1}{4 \pi \epsilon_0} \frac{\mathrm{q}^2}{\mathrm{r}} \\
& \Rightarrow \mathrm{r}=\frac{\mathrm{e}^2}{4 \pi \epsilon_0 \mathrm{mc}^2}
\end{aligned}$
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This is a previous-year question from JEE Main 2013, covering the Units and Dimensions 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.