JEE Main 2021 — Electromagnetic Waves Question with Solution
From: JEE Main 2021 (Online) 17th March Morning Shift
Question
If 2.5 106 N average force is exerted by a light wave on a non-reflecting surface of 30 cm2 area during 40 minutes of time span, the energy flux of light just before it falls on the surface is ___________ W/cm2. (Round off to the Nearest Integer)
(Assume complete absorption and normal incidence conditions are there)
(Assume complete absorption and normal incidence conditions are there)
Enter your answer
Show full solutionCorrect answer: 25
Correct answer
25
Step-by-step explanation
Pressure = (for absorbing surface)
I = P C
I = N 3 108 m/s
I = 25 W/cm2
I = P C
I = N 3 108 m/s
I = 25 W/cm2
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