Question

Find the 

1. Maximum frequency, and 

2. Minimum wavelength of X-rays produced by 30 kV electrons.

Answer 1

Given V₀ = 30 kV = 30 × 10³ V

v_max = ?

λ_max = ?

1. Since k_max = eV₀

So hv_max = eV₀

or

v_max = \(\frac{eV_0}{h}\)

= \(\frac{1.6\times10^{-19}\times30\times10^3}{6.62\times 10^{-34}}\)

= 7.24 × 10¹⁸ Hz

2. λ_min = \(\frac{c}{λ_{max}}\) = \(\frac{3\times10^8}{7.25\times10^{18}}\)

= 0.041 × 10^-9 

or λ_min = 0.041 nm