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Magnetism And Matter — Physics STD 12 Science — Question

Gujarat BoardEnglish MediumSTD 12 SciencePhysicsMagnetism And Matter1 Mark
MCQ
Two statements are given$-$one labelled Assertion $(A)$ and the other labelled Reason $(R)$. Select the correct answer to these questions from the codes $(a), (b), (c)$ and $(d)$ as given below.
Assertion $(A):$ Magnetic moment is measured in joule/ tesla or $\text{amp m}^2$.
Reason $(R):$ Joule/ tesla is equivalent to amp $m^2$.
  • ✓
    Both $A$ and $R$ are true and $R$ is the correct explanation of $A.$
  • B
    Both $A$ and $R$ are true but $R$ is $\text{NOT}$ the correct explanation of $A.$
  • C
    $A$ is true but $R$ is false.
  • D
    $A$ is false and $R$ is also false.
✓

Answer

Correct option: A.
Both $A$ and $R$ are true and $R$ is the correct explanation of $A.$
Magnetic moment $=\frac{\text{joule}}{\text{tesla}}=\frac{\text{W}}{\text{B}}=\frac{\text{W}}{\text{F/qv}}$
$=\frac{\text{Wqv}}{\text{F}}=\frac{[\text{MF}^2\text{T}^{-2}][\text{AT}[\text{LT}^{-1}]]}{[\text{MLT}^{-2}]}$
$=[\text{AL}^2]=\text{amp m}^2$

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