P-N Junction Diode and its applications: Practice Problem & Solution
Assertion (A): The semiconductor used for fabrication of visible LED must at least have a band gap of 1.8 eV. Reason (R): The spectral range of visible light is from 0.4 eV to 1.8 eV.
Short Solution (Best for NEET):
To solve this problem, we apply the core principles of P-N Junction Diode and its applications. Understanding the underlying formula is key to arriving at the correct answer below:
For visible light emission, the photon energy must be within the visible spectrum, which corresponds to energies from approximately \(1.8\) to \(3.1 \text{ eV}\). Thus, Assertion (A) is true. Reason (R) states the range from \(0.4\) to \(1.8 \text{ eV}\), which is incorrect for visible light.
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