The intensity of X-rays form a Coolidge tube is plotted against wavelength `lambda` as shown in the figure. The minimum wavelength found is `lambda_c` and the wavelength of the `K_(alpha)` line is `lambda_k`. As the accelerating voltage is increased
(a) `lambda_k - lambda_c` increases (b) `lambda_k - lambda_c` decreases
(c ) `lambda_k` increases (d) `lambda_k` decreases

Options

A. `(lambda_(k)-lambda_(c))` increases
B. `(lambda_(k)-lambda_(c))` decreases
C. `lambda_(k)` increases
D. `lambda_(k)` decreases

Answer

A

Explanation

Wavelength `lambda_(k)` is independent of the accelerating voltage (V), while the minimum wavelength `lambda_(c)` is invrsely Proportional to V.Therefore ,as V increases `lambda_(k)` reamins unchanged whereas `lambda_(c)` decreases ro `lambda_(k)-lambda_(c)` will increase.