Which of the following statements are true?

Options

A. The shortest wavelength of X-rays emitted from an X-ray tube depends on the corrent in the tube.
B. Characteristic X-ray spectra is simple as compared to optical spectra.
C. X-ray cannot be different by means of an ordianary grating.
D. Three exist a sharp limit on the short wavelength side for each continous X-ray spectrum

Answer

B, C, D

Explanation

Statement (a) is false. The shortest wavelength of the X-ray emitted depend on the energy of the electrons incident on the target . This , in turn , depends on the potential through which they have fallen . In fact
`lambda_(min) = (hc)/(eV)`
Statement (b) is true. X-ray spectra of all heavy elements are similar in character.
Statement ( c) is also true. The shortest wavelength of the X-rays `("compared to the greating constant of optical grating")` makes it difficult to observe X-ray differaction with ordianery gratings.
Statement (d) is also true. The sharp limit on the short wavelength side is dependent on the voltage applied to the incident electron and is given by :
`lambda_(min) = (hc)/(eV)`