The typical wavelength of $X$-ray is

Characteristic $X$-rays:

The minimum frequency $\nu$ of continuous $X$-rays is related to the applied potential difference $V$ as

The binding energy of the innermost electron is $40 \, keV$. To obtain characteristic $X$-rays using a tungsten target in an $X$-ray tube,the potential difference $V$ between the cathode and the anode must be:

The range of wavelength for $X$-rays is from . . . . . . .

For the production of $X$-rays of wavelength $0.1 \mathring{A}$,the minimum potential difference required will be.....$kV$.