Frequencies of Kα X-rays of different materials are measured. Which one of the graphs in figure may represent the relation between the frequency v and the atomic number Z.

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Moseley’s equation is given by:


where, “a” represents the proportionality constant while “b” represents the screening constant and Z is the atomic number of the element.
Squaring both sides, we get
So the graph should resemble a parabola (y=x2)

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