Question

Given that the minimum X-ray wavelength emitted is 31.08 pm when 40 keV
electrons strike a target, determine Planck's constant.​

Answer 1

Explanation:

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Answer 2

Planck's constant is :

Given : wavelength, λ = 31.08 pm

Energy = 40 keV, c = 3×10^8 m/s

We know that,

E = hc / λ

Where, h = Planck's constant

c = velocity of light

λ = wavelength

h = E×λ / c

= 40×10^3×31.08×10^-12 / 3×10^8

= 4.14×10^-15 eV/s