Question

Calculate the minimum wavelength (λ0) for the continuous spectrum of X-rays emitted when.. a) 30-kV electrons strike a cobalt (Co) target
b) 60-kV electrons strike a copper (Cu) target

Answer 1

Explanation:

The relationship between the wavelength and the potential difference V is given by :

$\lambda=\dfrac{h}{\sqrt{2me}}\times \dfrac{1}{\sqrt{V}}$

Putting the values of known parameters,

$\lambda=\dfrac{12.28}{\sqrt{V} }\times 10^{-10}\ m$

(a) $V=30\ kV=30000\ V$

$\lambda=\dfrac{12.28}{\sqrt{30000} }\times 10^{-10}\ m$

$\lambda=7.08\times 10^{-12}\ m$

(b) $V=60\ kV=60000\ V$

$\lambda=\dfrac{12.28}{\sqrt{60000} }\times 10^{-10}\ m$

$\lambda=5.01\times 10^{-12}\ m$

Hence, this is the required solution.