Question

The intensity of X- ray from a coolidge tube is plotted againest wavelength `lambda` as shown in the figure . The minimum wavelength found `lambda_(c)` and the wavelength of the` k_(a)` line is `lambda_(lambda)`, As the accelerating voliage is increase

A. `lambda_(lambda) -lambda_(c) ` increase
B. `lambda_(lambda) -lambda_(c) ` decrease
C. `lambda_(lambda)` increase
D. `lambda_(lambda)`decrease

Answer 1

Correct Answer - A
KEY CONCEPT :
In case of Coolidge tube
`lambda_(min) = (hc)/(eV) = lambda `(as given here)
This the cut off wavwlength is inversely proportional to accelerationg vollage . As `V` increase `lambda_(c)`decreases lambda_(k)` is the wavelength of `k_(prop)` line which is a characteristic of as atom and does not depensid on accelerating vollage of bombarding electron since `lambda_(k)` always to a photon wavwlength of transation of e^(bar) from the target element from `2 rarr 1`
The above two facts lead to the conclusion that `lambda_(k) - lambda_(c) ` increases as accelectrating voltage is increased