2. Choose the correct answer Initial X-ray flux is attenuated I in a substance , in accordance with the law: Phi =Phi _(0)e^-mu x Phi =Phi _(0)mu x^-2 Phi =Phi _(0)/mu x Phi =Phi _(0)(-ln(mu x))

The correct answer is: Explanation: The given equation represents the attenuation of the initial X-ray flux ( ) in a substance, where is the attenuation coefficient and is the thickness of the substance. The correct equation is , which describes the exponential decay of the flux as it passes through the substance.