a. X-ray are electromagnetic waves because these are producted by the deceleration of fast moving electron .
b. X-ray are electromagnetic waves because these produce line spectrum.
c. the cut-off wavelength depends on the target metarial .
d. The intensity of `K_(alpha)` transition is more probable then of `K_(beta)`
e The transition.
e. Frequency of `K_(alpha)` radiation is more than that of `K_(beta)`.

Explanation

a. True, According to the theory of electromagnetion , electromagnetic waves are generated by the acceleration or relardation of charges.
b. True, Line spectrum of electromagnetic waves are producedced due to the transition of electron from the higher level to the lower level.
c. False, The cut-off wavelength depends only on the kinetic energy of the striking electrons.
d. True, The `K_(alpha)` transition is more probable then the `K_(beta)` transition.
e. False Frequency of `K_(beta)` is more than that of `K_(alpha)` becouse `lambda_(B) gt lambda_(A)` as shown:
`(1)/(lambda_(beta)) = R_(oo) (Z-1)^(2) [(1)/(1^(2)) - (1)/(3^(2))] = (8)/(9) R_(oo) (Z-1)^(2)`
and `(1)/(lambda_(alpha)) = R_(oo) (Z-1)^(2) [(1)/(1^(2)) - (1)/(2^(2))] = (3)/(4) R_(oo) (Z-1)^(2)`