Question

The intensity (1) of X-rays after traversing a distance x through a matter is related to the coefficient of absorption $\left(\mu \right)$ of the material as

• A. $I=I_0{e}^{\mu x}$
• B. $I=I_0{e}^{-\mu x}$
• C. $I=e^{\mu x}/I_0$
• D. $I=e^{-\mu x}/I_0$

Answer 1

The correct option is B $I=I_0{e}^{-\mu x}$

The intensity follows the relation.
$\frac{dI}{dx}=-\mu I$
integrating this relation we get.
$ln\left(\frac{I}{I_0}\right)=-\mu x$
i.e.
$I=I_0{e}^{-mux}$
Hence option B is correct.