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MHT CET Medical202625 April 2026Evening ShiftPhysicsSemiconductorsActual

The color of light emitted by an LED is determined primarily by which of the following factors?

Options

  1. AThe forward current flowing through the junction.
  2. BConcentration of doping materials in the p-n junction.
  3. CThe physical dimensions of light-emitting diode.
  4. DThe band gap energy of the semiconductor material used.

Correct answer

D. The band gap energy of the semiconductor material used.

Step-by-step solution

The energy of the photon emitted by a light-emitting diode (LED) is approximately equal to the band gap energy E_g of the semiconductor material used. The wavelength of the emitted light is related to the band gap energy by the equation: = hc E_g Since the color of the emitted light depends on its wavelength , it is primarily determined by the band gap energy of the semiconductor material. Answer: The band gap energy of the semiconductor material used.

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