The wavelength of `K_(alpha)` X-ray for an element is 21.3 pm. It takes 11.3 ke V to knock out an electron from the L-shell of the atom of the element. What should be the minimum accelerating voltage across on X-ray tube having the element as target which allows production of `K_(alpha)` X-ray?

Explanation

Here lambda =21.3xx10^-12p m `
` Now , E_X-E_L=1242/(21.3xx10^-3) `
` =58.309KeV `
` E_L=11.3Kev, `
` Now V_e=69.609KeV `
` or v=69.6009KV `