Browse by Stream
Discuss Doubts
Home
Search for Exam, Articles, Questions
get app
Go To Your Study Dashboard
  1. Home
  2. A red led emits light at 0.1 watts uniformly around it. The amplitude of the electric field of the light at a distance of 1m from the diode is
# Engineering

A red led emits light at 0.1 watts uniformly around it. The amplitude of the electric field of the light at a distance of 1m from the diode is

Answers (1)
L Lovekush Kumar Saini

As we learnt in

LED (Light emitting diode) -

It gives out light radiation when forward biased .

- wherein

LED's are made of GaAsP  ,Gap etc .

(Require low voltage ,long life )

 

 I=\frac{P}{4\pi r^{2}}=\frac{0.1}{4\pi}=U_{av}.C

Amplitude I = E0

U_{av}=\frac{1}{2}\epsilon_{0}E_{0}^{2}

\Rightarrow\ \; \frac{1}{2}\epsilon_{0}E_{0}^{2}=\frac{0.1}{4\pi C}

or  E_{0}^{2}=\frac{0.2}{\left(4\pi \epsilon_{0} \right )C}=\frac{0.2\times 9\times 10^{9}}{3\times 10^{8}}=6

\therefore\ \;E_{0}=2.45\ V/m

Similar Questions

Preparation Products

Knockout JEE Main Sept 2020

An exhaustive E-learning program for the complete preparation of JEE Main..

₹ 12999/- ₹ 6999/-
Buy Now
Rank Booster JEE Main 2020

This course will help student to be better prepared and study in the right direction for JEE Main..

₹ 9999/- ₹ 4999/-
Buy Now
Test Series JEE Main Sept 2020

Take chapter-wise, subject-wise and Complete syllabus mock tests and get in depth analysis of your test..

₹ 4999/- ₹ 1999/-
Buy Now
Knockout JEE Main April 2021

An exhaustive E-learning program for the complete preparation of JEE Main..

₹ 22999/- ₹ 14999/-
Buy Now
Knockout JEE Main April 2022

An exhaustive E-learning program for the complete preparation of JEE Main..

₹ 34999/- ₹ 24999/-
Buy Now
Exams
Articles
Questions