The potential difference applied to an $X$-ray tube is $5 \text{ kV}$ and the current through it is $3.2 \text{ mA}$. Then the number of electrons striking the target per second is

$X$-rays region lies between

The shortest wavelength of $X-$rays emitted from an $X-$ray tube depends upon

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.

Assertion : Soft and hard $X-$ rays differ in frequency as well as velocity.
Reason : The penetrating power of hard $X-$ rays is more than the penetrating power of soft $X-$ rays.

In producing $X$-rays,a beam of electrons accelerated by a potential difference $V$ is made to strike a metal target. For what value of $V$ will the $X$-rays have the lowest wavelength of $0.3094 \ \mathring{A}$? (in $kV$)