$X$-rays region lies between

The energy of the $K_\alpha$ $X$-ray line of an element is $8578$ units,and the energy of the $L$ level is $-2859$ units. The energy of the $K$ level is . . . . . . units.

The diagram shows a graph between the intensity of $X$-rays emitted by a molybdenum target and the wavelength,when electrons of $30 \ keV$ are incident on the target. In the graph,one peak corresponds to the $K_\alpha$ line and the other peak corresponds to the $K_\beta$ line.

The wavelength of $X-$rays is of the order of

Electrons of mass $m$ with de-Broglie wavelength $\lambda$ fall on a target. The cut-off wavelength $\lambda_0$ is equal to [$h=$ Planck's constant,$c=$ velocity of light].

In an $X-ray$ tube, the voltage is $5 \, kV$ and the current is $3.2 \, mA$. The number of electrons striking the anode per second is: