The colour of light emitted by an LED depends upon | PGMN Solutions

The colour of light emitted by an LED depends upon
(A) its forward bias
(B) its reverse bias
(C) its size and shape
(D) the band gap of the material of the semiconductor



______________________________________________________



🚀 Step-by-Step Solution to Solve This Question 🚀
📌 Chapter: Semiconductor Device
📌 Topic: Light Emitting Diode (LED)

🔹 Step 1: Understand how an LED works
An LED emits light when it is forward biased, and electrons recombine with holes, releasing energy in the form of photons.

🔹 Step 2: Know what decides the energy of the emitted photons
The energy released in each recombination is related to the band gap of the semiconductor material used in the LED.

🔹 Step 3: Relate energy to colour
Different band gaps result in different photon energies, and these energies correspond to specific colours of visible light. So, the band gap determines the colour of light emitted.

🔹 Step 4: Eliminate other options

Forward bias enables the LED to work but doesn’t decide the colour.

Reverse bias doesn’t make the LED emit light.

Size and shape affect brightness or intensity, not the colour.

✅ Final Answer: (D) the band gap of the material of the semiconductor 🚀

🔥 Pro Tip:
Always link the colour of light in LEDs with the band gap—larger band gaps emit higher energy (bluer light), and smaller ones emit lower energy (redder light).


________________________________________________________


📽️ Must watch if you're preparing for MHT-CET 2025 Physics. Perfect for concept clarity & revision.

Welcome to PGMN Solutions – your go-to channel for MHT CET Physics solutions!
🚀 One Question, One Solution – Every Day! 🚀

📌 Get step-by-step solutions to past MHT CET Physics questions, explained by Mukesh Sir.
📌 Master concepts, improve speed, and ace your MHT CET exam with expert guidance.
📌 All solutions are from previous years and important expected questions.

🔔 Subscribe now for daily updates & never miss a solution!
🌐 Visit www.pgmn.live for more Physics resources, test series, and full courses.