#### Question

The X-ray coming from a Coolidge tube has a cutoff wavelength of 80 pm. Find the kinetic energy of the electrons hitting the target.

(Use Planck constant h = 6.63 × 10^{-34} Js= 4.14 × 10^{-15} eVs, speed of light c = 3 × 10^{8} m/s.)

#### Solution

Given:-

Cutoff wavelength of the Coolidge tube, `lambda = 80 "pm"`

Energy of the electron hitting the target (E) is given by

`E = (hc)/lambda`

Here,

h = Planck's constant

c = Speed of light

λ = Wavelength of light

`therefore E = (1242 "eV"-"nm")/(80 xx 10^-3)`

`⇒ E = (1242 xx 10^-9 "eV")/(80 xx 10^-12)`

`⇒ E = 15.525 xx 10^3 "eV" ≈ 15.5 "keV"`

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#### APPEARS IN

Solution The X-ray Coming from a Coolidge Tube Has a Cutoff Wavelength of 80 Pm. Find the Kinetic Energy of the Electrons Hitting the Target. Concept: Electromagnetic Spectrum.