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An LED is constructed from a p-n junction diode using GaAsP. The energy gap is 1.9 eV . The wavelength of the light emitted will be equal to

Options

  1. A10.4 10⁻²⁶ ~m
  2. B654 ~nm
  3. C654 Å
  4. D654 10⁻¹¹ ~m

Correct answer

B. 654 ~nm

Step-by-step solution

The energy of light of wavelength is given by E = hv = hc = hc E Here, h = Planck's constant =6.63 10⁻³⁴ ~J - s c = speed of light =3 10^8 ~m / s E = energy gap =1.9 eV =1.9 1.6 10⁻¹⁹ ~J Substituting the given values in Eq. (i), we get aligned & = 6.63 10⁻³⁴ 3 10^8 1.9 1.6 10⁻¹⁹ & =6.54 10⁻⁷ ~m 654 ~nm aligned Thus, the wavelength of light emitted from LED will be 654 ~nm .

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