Semiconductor Electronics
Class 12 · Semiconductor Electronics · Practice
LED Behavior — Previous-Year Questions
5 previous-year questions on LED Behavior, drawn from JEE Mains, JEE Advanced, NEET UG, and CUET papers. Every question carries a worked-out explanation.
Q1. An LED emits red light at ~620 nm. Its band gap is approximately:
JEE 2022Q2. Why are LEDs typically made of GaAs and not Si?
JEE 2021Q3. Forward voltage of a blue LED is typically:
JEE 2020Q4. An LED needs 20 mA at 2.0 V. Series resistor from a 5 V supply:
JEE 2019Q5. Power dissipated in the LED above:
JEE 2018LED Behavior previous-year questions from sciphylab (also known as SciPhy, SciPhy Lab, SciPhy Labs, Physics Lab). Class 12 physics practice for JEE Mains, JEE Advanced, NEET UG, AP Physics 1/2/C, SAT, and CUET-UG candidates.