Sign Up to our social questions and Answers Engine to ask questions, answer people’s questions, and connect with other people.
Login to our social questions & Answers Engine to ask questions answer people’s questions & connect with other people.
Lost your password? Please enter your email address. You will receive a link and will create a new password via email.
Please briefly explain why you feel this question should be reported.
Please briefly explain why you feel this answer should be reported.
Please briefly explain why you feel this user should be reported.
Question 12: NCERT Solutions for 12th Class Physics: Chapter 8-Electromagnetic Waves
About 5% of the power of a 100 W light bulb is converted to visible radiation. What is the average intensity of visible radiation
(a) at a distance of 1 m from the bulb?
(b) at a distance of 10 m?
Assume that the radiation is emitted is o tropically and neglect reflection.
Solution:
The bulb as a point source, radiate light in all direction uniformly and it is given that only 5% of power is converted to visible radiations.
(a) Let us assume a sphere of radius 1 m. Surface area A = 4πr2 = 4π (l)2 = 4 π m2 Intensity on the sphere
(b) Let us assume a sphere of 10 m radius. Surface area A = 4π2 = 4K (10)2 = 400 π m2 Intensity on the sphere
Check the complete chapter with solutions.
NCERT Solutions for 12th Class Physics: Chapter 8-Electromagnetic Waves