The energy of a photon of characteristic $X-$ rays from a Coolidge tube comes from

$A$ charged gold leaf electroscope has its leaves apart by a certain amount with enclosed air. When the electroscope is subjected to $X$-rays,then the leaves

Consider the following two statements $A$ and $B$ and identify the correct choice in the given answer.
$A:$ The characteristic $X-$ray spectrum depends on the nature of the material of the target.
$B:$ The short wavelength limit of the continuous $X-$ray spectrum varies inversely with the potential difference applied to the $X-$ray tube.

$X$-rays are not used for radar purposes because:

In the characteristic $X$-ray spectra of an atom superimposed on a continuous $X$-ray spectrum, identify the peaks $P$ and $Q$ shown in the graph.

$X$-rays,when incident on a metal,do which of the following?