question_answer

\[{{K}_{\alpha }}\,and\,{{K}_{\beta \,}}X-rays\] are emitted when there is a transition of electron between the levels

A)  \[n=2\] to \[n=1\] and \[n=3\] to \[n=1\] respectively

B)  \[n=2\] to \[n=1\] and \[n=3\] to \[n=2\]respectively

C)  \[n=3\] to \[n=2\] and \[n=4\] to \[n=2\]respectively

D)  \[n=3\] to \[n=2\] and \[n=4\] to \[n=3\]respectively  

Correct Answer: A

Solution :

When the colliding electron remove an electron from innermost K-shell (corresponding to n = 1) of atom and electron from some higher shell jumps to K-shell to fill up this vacancy, characteristic X-ray of K-series are obtained \[\therefore \]\[{{K}_{\alpha }}\] and \[{{K}_{\beta }}\] X-rays are emitted when there is transition of electron between the levels \[n=2\] to \[n=1\]and \[n=3\] to \[n=1\] respectively.