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Units, Dimensions and Measurement — JEE physics STD 12 Science — Question

CBSE BoardEnglish MediumSTD 12 ScienceJEE physicsUnits, Dimensions and Measurement1 Mark
Question
Assertion : A.U. is much bigger than $\mathring A$.
Reason : A.U. stands for astronomical unit and $\mathring A$ stands from Angstrom.
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Answer

(b) A.U. is used (Astronomical units) to measure the average distance of the centre of thesun from the centre of the earth, while angstrom is used for very short distances. 1 A.U. = $1.5\times 10^{11} \mathrm{~m} ; 1 . \hat{A}=10^{-10} \mathrm{~m}$.

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